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1. 4 TRACE OF LAST 10 BRANCH INSTRUCTIONS EXECUTED BEFORE TERMINATION PSW BITS SHOWN ARE THOSE JUST BEFORE CORRESPONDING INSTRUCTION DECODED IM LOCATION INSTRUCTION IM PSW BITS 32 39 ILC CC MASK BEFORE INSTRUCTION EXECUTED AT PROGRAM LOCATION SHOWN AA BBBBBB CEES CECE CCCG 1 10 lines in this format The above section of the Assist Completion Dump is only given when ASSIST Optional Extended Interpreter is in use by the installation This section in a dump lists up to the last 10 successful branch instructions xecuted before termination SE GP REGISTERS 0 8 1 9 2 10 3 11 4 12 5 13 6 14 7 15 REGS 0 7 8 groups of 8 hexadecimal digits each REGS 8 15 8 groups of 8 hexadecimal digits each FLTR 0 6 4 groups of 16 hexadecimal digits each The above section in a dump displays the contents of the user s general purpose and floating point registers at the time of termination ASSIST5 14 6 USER STORAG E CORE ADDRESSES SPECIFIED XXXXXX TO yyyyyy ZZZLZZZ 8 groups of 8 hexadecimal digits each 32 characters The above section shows the format of a user storage dump The beginning and ending addresses are given by xxxxxx and yyyyyy Each line shows 32 bytes beginning at location zzzzzz grouped into eight fullwords Each area is also shown in alphameric form at the right with blanks letters
2. PART I CONTINUED APPENDIX Ki USE OF LIBRARY MACROS o a cuscecece 6 ee acens rea ed fe 1 12 PART II INPUT OUTPUT AND DEBUGGING INSTRUCTIONS 251 INPUT OUTPUT INSTRUCTIONS XREAD XPRNT XPNCH 2 1 CONDITION CODE aos init lot toe is Bis Phi sal dio Op sete 2 1 CARRTAGE CONTRO Eat A RAE ARAS 2 1 EXAMPLES OF XREAD XPRNT XPNCH USAGE o ooooooooo 2 2 DEBUGGING INSTRUCTION ADUMP a e we ee ee 2 3 GENERAL PURPOSE REGISTER DUMP o oooooooo o o 2 3 STORAGE DUMP ta iS EE ara A E e ata 2 3 EXAMPLES OF XDUMP USAGE so rna aea es Sie bee ee ee Ee LS 2 3 DECIMAL CONVERSION INSTRUCTIONS XDECI XDECO 2 4 A E co forte so isthe oe ay hve Tega les aries Tob ANO 2 4 PDE Ossie sor E AAA AS yA Se BESO Leh AA Dek 2 4 SAMPLE USAGE OE XDEGA 6 see ES a wise ele eee tee ee 2 5 SAMP Dik USAGE OE ADE CO ce ieee a e series een ete e 2 5 HEXADECIMAL CONVERSION INSTRUCTIONS XHEXI XHEXO 2 6 LEAL a e E A ce ue erie Sapte ote E AAA ee Ob Locate ve meg UES de 2 6 X AEX a A ao O eaa aa Baers a eae te ee 2 6 SAMPLE USAGE OF XHEXI AND XHEXO o ooooooooo eee ee eee 2 7 CEMI T DUMP TNSTRUCTTON XLTMD Sora ie Bridie lie Ris leew le 2 8 SAMPTIE USAGE OP ALIMD cc A da 2 8 OPTIONAL INPUT OUTPUT INSTRUCTIONS XGET XPUT 2 9 CONDE TION CODES A aie ey olcleate ores 2 9 CARRIAGE CONTRO Lara am a ener 2 9 EXAMPLES OF XGET AND XPUT USAGE
3. a ASSIST version OF date INSTS DFP CHECK TRP OPTS CCKMR PENN STATE UNIV model system This heading is the first line printed and it describes th facilities in the version of ASSIST being used as follows version date version number of this ASSIST and date it was created INS DFPS describes instruction sets accepted The digits are 0 s or 1 s showing lack or presence of decimal floating point privileged operations and some S 370 operations CHECK TRP describes time records and pages checking modes a 2 for T or R indicates ASSIST can obtain time or records remaining from system 0 for T indicates no timing 0 for P indicates no page checking possible OPTS CCKMR describes availability of major optional features in order CMPRS COMNT KP 26 MACRO and REPL Values of O indicate the feature is unavailable If value for COMNT is nonzero it is two digits long and gives the percentage of comments required A value of 1 for R denotes a partial version of the Replace Monitor while 2 denotes a complete version with all features model lists the model number of the computer being used system describes operating system being used such as OS MVT Dis Following the above heading the ASSIST monitor prints the contents of the user s EXEC card PARM field or his SJOB CARD E xxx PROGRAM E
4. Col 1 Col 8 Columns 16 80 of card 1 J Jl 1 SJOB ASSIST list of options separated by commas The first of these may be an account number which is ignored by ASSIST All others are optional Dye Saad 360 assembler source deck or ASSIST object deck 3 SENTRY this card must be present if user execution is to occur regardless of existence of data A Rh data cards to be read by user program optional If the user desires only an assembly of his program the SENTRY card should be omitted As many of the above can be included in one batch submitted to ASSIST with BATCH and other appropriate parameters supplied to ASSIST in the invoking PARM field The batch can be ended in one of two ways ither an end of fil indicator or a card with the following in columns 1 5 S STOP The entire batch of runs is run with whatever enclosing Job Control Language is required for a given installation by specifying BATCH in the invoking PARM field All versions of ASSIST can run BATCH programs but not all can run them with the SINGLE RUN DECK SETUP A sample BATCH run is given below a JOB card EXEC ASACG PARM BATCH other options if any SYSIN DD SJOB ASSIST ACCT1 options Sheed ie ule more jobs each beginning with JOB cards or a STOP card ASSIST3 2 B OPTIONAL PARAMETERS FOR ASSIST ASSIST provides a large number of options to control the ac
5. A brief note on the XREF mechanism is necessary to make use of the flexible control provided During Pass 1 of an assembly the SD symbol Definition flag is attached to each symbol as it is defined The flag consists of two bits M for Modify and F for Fetch in that order and shows for each symbol what kinds of references may possibly collected For example SD 10 indicates that no Fetch references ar ver to be printed for a specific symbol The SD flag may be changed during a program by XREF cards so that symbols in different sections of the program can be treated differently SD 00 will eliminate all following symbols completely until it is changed again During Pass 2 a Symbol Reference SR flag is used to determine what types of references are being collected from the code A reference to a symbol is logged if and only if the SD bit and the SR bit for the given type of reference are both on I e if SD 10 for a symbol SR 11 at the current time and a fetch reference is made no reference will be logged since the SD Fetch bit is 0 Note that references ar only logged during Pass 2 some symbol references occur only during Pass 1 and these are ignored such as sumbols in EQU ORG and DC and ODS length modifiers or duplication factors The XREF parameter requests a cross reference indicates th typ of output produced and possibly gives initial values to the SD and SR
6. SECTION 2 GENERAL INFORMATION General Restrictions on Symbols A symbol may be defined only once in an assembly i e it may appear in the name field of no more than one instruction The same symbol may not be used as a label in two different control sections and control sections may not be resumed the only Case in the standard language allowing the same symbol on more than one statement Location Counter Reference ASSIST allows full use of the location counter with the following exceptions 1 The programmer may not refer to the location counter inside a literal address constant Thus the following statement will produce incorrect results L 1 A 20 2 The programmer may not refer to the location counter in an A type address constant having a duplication factor greater than one if the reference is made in such a way that the various duplications of the specified constant have different values For instance under 0OS 360 the following statement would produce the values 0 1 255 but ASSIST would produce 256 bytes of zero NAME DC 256AL1 NAME Literals Literal constants may not contain more than 112 characters counting the beginning and ending delimiter i e may not require more than two cards when placed in the literal pool Literal Pool Unless otherwise specified by the use of the LTORG instruction the literal pool is placed after the program s END card rather tha
7. EXAMPLES OF XDUMP USAG E DUMP AREA 10 80 DUMP 8 1 4 100 DUMP FULLWORD use default value of 4 DUMP TABL 3 12 X X X X ASSIST2 4 DECIMAL CONVERSION INSTRUCTIONS XDECI XDECO To facilitate numeric input output ASSIST accepts the commands XDECI eXtended DECimal Input and XDECO eXtended DECimal Output XDECI can be used to scan input cards for signed or unsigned decimal numbers and convert them to binary form in a general purpose register also providing a scan pointer in register 1 to the end of the decimal number XDECO converts the contents of a given register to an edited printable decimal character string Both instructions follow the RX instruction format as shown XDEC REG ADDRESS where REG is any general purpose register and ADDRESS is an RxX type address such as LABEL O R4 R5 LABEL 3 2 XDECI XDECI is generally used to scan a data card read by XREAD The sequence of actions performed by XDECI is as follows 1 Beginning at the location given by ADDRESS memory is scanned for the first character which is not a blank 2 If the first character found is anything but a decimal digit or plus or minus sign register 1 is set to the address of that character and the condition code is set to 3 overflow to show that no decimal number could be converted The contents of REG are not changed and nothi
8. flags Two forms are permitted as follows XREF a OR XREF a b c WHERE a indicates overall control and output format 0 no cross reference is generated 2 cross reference is printed with one symbol per output line 3 cross reference is printed but with minimal output wasted more than one symbol may appear on a line this form is recommended b initial value of SD flag in decimal corresponding to binary i e 0 00 LE Ol 228 310 dead Ci initial value of SR flag same format as b Illegal values are ignored and it is allowable to omit items as desired showing this by comma usage XREF 2 2 for example The default value is XREF 0 3 3 so that all that is needed to obtain a complete listing is to code XREF 2 or XREF 3 as the other values are not changed or zeroed ASSIST3 12 The SR and SD flags may be changed at any time during the program by placing XREF comment cards anywhere in the source program following the first machine instruction or assembler opcode used SD options used before these will work but SR s will be ignored The format is XREF one or more blanks OPTION1 valuel OPTION2 value2 The operand s may be specified in any order and if the same option is used several times requested actions are performed in order The options are SD lt M gt lt F gt give the modify and fetch bits for the SD flag SR lt M gt lt F gt giv
9. C24 3414 IBM SYSTEM 360 DISK AND TAPE OPERATING SYSTEM ASSEMBLER LANG The second section describes input output decimal conversion hexadecimal conversions and debugging facilities available to the user at execution time The third part of the manual describes th control cards and Job Control Language required to assemble and execute a program under ASSIST It also notes the various options from the PARM field which are accepted by the system The fourth section gives information concerning the output from ASSIST including the assembly listing the format of the completion dump produced by an error in program execution and a list of all error messages produced during assembly or execution It also describes the object decks produced accepted by ASSIST Note this document is NOT copyrighted Note only major change in documentation from version 2 1 is the inclusion of cross reference material XREF and the inclusion of th xtended interpreter material ASSIST1 2 TABLE OF CONTENTS PART I THE ASSEMBLY LANGUAGE UNDER ASSIST 1 4
10. n notes that the option CAN be set from the source 2 INVOKING PARM 3 JOB PARM 4 DEFAULT ndicates a numerical parameter which cannot ever ny previously set value under O column indicates an option which can be omitted from a particular generation of ASSIST to save space for instance FROM NO DEFAULT PURPOSE 1234 VALUE AND USAGE 1234 O ALGN suppress alignment specification errs H 12 NOBATCH indicate a batched type run CMPRS 1234 O NOCMPRS compressed source list 2 cols page COMNT 12 O NOCOMNT require percentage of commented cards CPAGE 12 O NOCPAGE control paging and page counting DEC 1234 O NODECK punch object deck DISKU 123 O NODISKU intermediate disk storage used DUMP 1234 0 controls type and size of dump FRE 12 4096 bytes returned to system for buffers I 1234 150000 maximum instructions for user prog KP 1234 O 029 type of keypunch used 026 or 029 1234 NO 63 maximum lines page if CPAGE on 1234 O NOLIBMC allow library macros to be printed 1234 LIST produce source listing of assembly 1234 LOAD produce object program and run it 1234 O N allows use and types of macros 1234 N O 200 default value of MACRO ACTR 1234 N O 15 maximum nest level for macro calls 1234 N O 4000 maximum total macro stmts processed 1234 0 maximum errors permitting execute 1234 O NOOBJIN object deck input rather than s
11. required to initiate test user test deck for replacement program optional if user wants assembled test program to execute also unlikely ng PARM field options are of particular interest to replacement facility see PART III of USER S GUIDE ed if the run is to be a replacement run rather than normal assembly and execution oded to initialize the value of the RFLAG for the entire The default value is 0 BATCH may be coded if the user wants to test more than one module or more than one version of the same module in the same run T number the instruction count limit specified applies to each call of acement module It is therefore recommended that this al operand be coded and that its value be fairly small a repl option ASREPLGD 10 PART IV REPLACE MONITOR MESSAGES The following lists the messages which may be produced during a replace run by the Replace Monitor Note that all thes messages ar printed inline with output produced by other sections of ASSIST In particular Replace Monitor output is embedded in the listing of the user test program which can possibly make it difficult to read in some cases A helpful procedure is to run the test program by itself under ASSIST thus obtaining a listing then insert a PRINT OFF command at the beginning This will remove most of he test program listing All Replace Monitor messages are of the form AR messag The type of messa
12. and digits printed directly and all other characters translated to periods D COMPLETION COD Gl S SYSTEM 0Cx This code is given for program interrupts where x is the hexadecimal interrupt code The message given is as shown on page 6 of the IBM System 360 Reference Data card for interrupts 0 F ASSIST xxx message This type is given for special ASSIST completions The possible codes and messages are as follows 220 ATTEMPTED READ PAST ENDFILE After performing an XREAD instruction and receiving an end of file indication the user has attempted another XREAD i e tried to read more data cards than existed 221 INSTRUCTION LIMIT EXCEEDED The user specified an I limit on his EXEC card and this number of instructions has been exceeded The program was probably looping 222 RECORD LIMIT EXCEEDED The user attempted to print or punch more records than was given by combination of R RD and RX option values Execution has been terminated and at least a partial dump given 223 TIME LIMIT EXCEEDED The user program has consumed more execution time than specified by the values of the T TD and TX option values Execution was terminated and at least a partial dump given 224 BRANCH OUT OF PROGRAM AREA The user program attempted to branch outside of its area The only branch outside not flagged this way is a branc
13. ooooooooooo oo 2 10 PART III ASSIST CONTROL CARDS AND DECK SETUP 3 1 A JOB CONTROL TANGUAGE a eons ia ode aras e a ads Whe aL econo 3 1 B OPTIONAL PARAMETERS FOR ASSIST oooooooooooooo noo ooo 3 2 Ce DESCRIPTION OF INDIVIDUAL OPTIONS ooooooooooooooooo 3 4 PART IV ASSIST OPTIONAL EXTENDED INTERPRETER 4 1 A GENERAL DESCRIPTION OF NEW FEATURES oooooooooo o 4 1 B THE XOPC Assist OPtions Call DEBUGGING INSTRUCTION 4 2 PART V OUTPUT AND ERROR MESSAGES ooooooooooomooooo 5 1 Ast AS SEMBEY GEST EN Gee ase evie dia e year it ess g 1s ASSEMBLY LISTING EORMAT d pietines ie ala Buc e 6 io level ened acia 31 2 ASSEMBLER BRROR MESSAGES ias ore SH 3 LIST OF ASSEMBLER ERROR MESSAGES oo o oooooooooo 5 2 4 ASSEMBLER STATISTICS SUMMARY ooooooooooooooooo 5 10 Be ASSIST MONTTIOR MESSAGES ei Ee lense e a aain adenina 6 eae due esa et ILL 1 HEADING AND STATISTICAL MESSAGES oo ooooooooo o 5 11 2 ASSIST MONITOR ERROR MESSAGES seo olen aee a o a iniii as 5 12 Es ASSTS 1 COMPLET FON Ss DUMPS tos ia o e ie ds ere der engl idos 5 13 Dis COMPLETT N CODES Litas iS Steed Sus Seep sens E we Mens eee 5 14 E OBJECT
14. rong direction or DD card missing or not enough room in ables etc CARRIAGE CONTROL XPUT only requires the first character of the area to be a valid carriage control character if the output device is the printer CLOSING OF FILE Performing an XGET or XPUT with a length of zero supplied in any GP register causes the designated file to be closed so that it may then be reread I e LA 1 CL8 ddname SR 0 0 XGET area 0 does close EXAMPLE in parallel OF XGET AND XPUT USAG El AS SIST2 10 The following program will read and write a few files TESTI CSECT BALR 12 0 USING EZ SR 0 0 hi THIS PROGRAM WILL PROCESS A FEW FILES IN PARALLEL ake LOOP LA 1 CL8 CARD point to an input file XGET AREA 80 do the input BNE DONE branch on endfile E file automatically closed XREAD AREA2 80 do normal input LA 1 CL8 PAPER point to a printer file XPUT AREA 1 81 do output note carriage control LA 1 CL8 PAPER2 point to other printer file XPU AREA2 1 81 do output on other file B LOOP try again DONE BR 14 RETURN IMPLICITLY CLOSE OTHER FILES DC ELL A AREA DS CL80 DC CHIT 4 AREA2 DS CL80 END The extra JCL for the above is as follows DATA PAPER DD SYSOUT A DC
15. 026 keypunch was used to prepare the job while 29 specifies an 029 keypunch Leading zeroes ar permitted and any value except 26 implies an 029 keypunch Ls This is used to specify the maximum lines per page and is only enabled if the CPAGE option is turned on LIBMC NOLIBMC Coding LIBMC permits macros fetched from libraries to be printed if desired Only effecitve when MACRO is supplied to an ASSIST which supports macro libraries See also MACRO and APPENDIX K of PART I LIST NOLIST Coding NOLIST suppresses the printing of the assembly listing and can be used for relatively bug free programs However regardless of the current print status any statement flagged with an error or warning message is always printed ASSIST3 6 LOAD NOLOAD Under most circumstances a programmer usually wants to execute his assembler program If he just wants to check it for errors but not execute it the NOLOAD option can be coded This will result in slightly faster assembly times In addition it will require less space in memory and it may be possible to assemble a program under NOLOAD that cannot be assembled with the LOAD option MACRO This option notes whether macro processing is to be done and if so what language facilities are to be allowed The values allowed are MACRO N NO macro processing used if error in option MACRO F F level Assembler compatibility basic facility MACRO G G le
16. DECKS AND LOADER MESSAGES oooooooooooooooo 5 15 Te OBJECT DECK FORMAT uote eine a de Si oie yell ers ita 5 15 2 ASSIST LOADER USAGE AND MESSAGES 5 16 PART I THE ASSEMBLY LANGUAGE UNDER ASS This Assembler follows section deals with the s Languag accepted b th the standard very closely those language features which ASSIST The user for most headings publicati SECTION 1 Compatibi With should generally consult the of the information on the as and sub headings in this ma IST ubset of the standard OS 360 ASSIST assembler Because it the following describes only omits or treats differently previously mentioned publication sembler language The section nual are taken from the IBM on and any sections omitted may be assumed to be the same as the corresponding sections in the IBM manual INTRODUCTION lity a few possible exceptions any program which assembles and executes correctly under ASSIST should do same output as under ASSIST a change of Job Control Language might be necessary 0S 360 so At most ftware and should produce the so using the standard The Assembler Program The assembler program produces a listing of the source program and normally creates an object program directly in main memory while using no secondary storage unless requested An object deck can be punched
17. OF O The statement flagged is in an incorrect place in the deck LCLx before GBLx in middle of macro definition or open code May often be caused by missing M RDER ENSION ISSUED DURING MACRO PROCESSING extra operand was found i e an extra hose given in the prototype For ACTR not after both GBLx LCLx ACTR SYSLIB card out of END card ERROR or one which was not dimensioned was written with one AS204 INVALID NBR OF SUBSCRIPTS There was an error in specifying substring notation set symbol dimension sublists or ASSIST5 7 AS205 ILLEGAL CONVERSION During macro editing a SET instruction was found with an obviously Incorrect conversion as in amp I SETA C AS206 MISSING QUOTES IN CHAR EXPR Quotes apostrophes are required in character expressions and must always be supplied but were not AS207 ILLEGAL OR DUP MACRO NAME A macro prototype name is either completely illegal such as having too many characters or duplicates the name of a previously given macro machine instruction or assembler instruction AS208 OPRND NOT COMPATIBLE WITH OPRTR An operand is used with an incompatible operator For example if amp C is LCLC amp B LCLB amp B SETB NOT amp C AS209 UNDFND OR DUPLICATE KEYWORD In calling a macro a keyword is used which does not appear in the macro prototype In either defining or calling a macro a keyword o
18. REPLACEMENT Replace action is aborted and a dump given
19. ROGRAM USING XHEXI AND XHE reads a data The end of the data is denoted by a punched The numbers ar ILLEGAL CHARACT INSTRUCTIONS E ASSIST2 7 card with an unknown number of hexa KNOQHNVVAQPMADWDSE ER IN R2 IS stored after being converted EXO H BERS STORED E CARD PRINT D OF CARD FOR SCANNING ON NUMBER PUT IN 2 H R END UT NUMBER IN OUTPUT AREA RINT CARD AND MESSAGE TOR BER NCR 1 INDEX E NUMBER E END OF STRING P1750 FOR CARD FOR NUMBERS STORAG FOR OUTPUT NUMBER ASSIST2 8 LIMIT DUMP INSTRUCTION XLIMD In order to conserve output records when necessary for instance when ASSIST is being used from a remote terminal of any sort the XLIMD instruction is provided to enable the user to limit the size of his completion dump and choose the area to be printed In general it is used to eliminate the user s program code leaving only his data areas in the completion dump The instruction is coded as follows XLIMD area length area is the beginning address where the completion dump should start The area address is specified by an RX type address and must be within the user program area length is the length in bytes of th area th user wishes to be printed if a completion dump occurs Note that the XLIMD instruction format is exactly the same a
20. SECTION CODING The assembler requires that any section be coded in one piece The label flagged has already appeared on a CSECT or ODSECT AS108 ILLEGAL DUPLICATION FACTOR A duplication factor either exceeds the maximum value of 32 767 or a dupl a decimal lication factor in a literal constant is not term or else has the value zero specified by AS109 EXPRESSION TOO LARGE The value of the flagged expression or term is too large for the given usage such as a constant length greater than the maximum permissible for the type of constant AS110 EXPRESSION TOO SMALL The value of the flagged expression or term is too small for the given usage or has a negative valu Coding a V type constant with a length of two would generate this message ASSISTO 4 AS111 INVALID CNOP OPERAND S The operands of a CNOP have values which are anything but the legal combinations of values for a CNOP such as a first operand greater than the second an odd value etc The only legal value combinations are 0 4 2 4 0 8 2 8 4 8 6 8 AS112 LABEL NOT ALLOWED A label is used on a statement not permitting one such as a CNOP or USING statement AS113 ORG VALUE IN WRONG SECTION OR TOO LOW The expression in an ORG statement either has a value smaller than the initial location counter value for the current control section or has a relocatibility attribute different from that of the current control
21. The sections flagged note that the given language features are not accepted by ASSIST SECTION Iie INTRODUCTION ye sosti ware due sede Wie eed ea aha es 1 4 COMmpatIbLITE Y wis said ats at dines toned ja eee did Dalle e cdl eces 1 4 Macro TNSERUCELONS oeeie Rites eed eee eee ane sens GLE aera 1 4 The Assembler Program lt i Sree a ee er Be ee a 13 SECTION 2 GENERAL INFORMATION o oooooooooooooooooooooo o L 5 AM O al aaa abans tte ate wee L 5 General Restrictions on SymbolS oooooooooooo ooo 1 5 Location Counter ReferenceS eee eee ee ee ee ee eee Las A O 1 5 irteera PO On aig so tense dr ia boe de 15 EXPLOSION Sis Sidi a ie tod Sad io LS ve Bie Si ta sc L 5 SECTION 3 ADDRESSING PROGRAM SECTIONING AND LINKING 1 6 USING Use Base REgGiSter ee ee eee ee ee eens 1 6 CONTROL SECTION S 4er aig ete a Bibi e dd We ee a ale ae 1 6 Control Section Location Assignment 1 6 ETRST CONTRO SECTION ba it ii ete TALE od eye eee Be oe 1 6 START Start ASSEMOLYs sles Siew oa e wae Bike a 1 6 CSECT Tdentity Control SQCEPOM vias wages lene deere ered ts 1 6 DSECT Tdentity DUMMY SECT seresa ened ies lee 1 6 EXTERNAL DUMMY SECTIONS ASSEMBLER F ONLY 1 6 COM DEFINE BLANK COMMON CONTROL SECTION 1 6 SECTION 4 MACHINE INSTRUCTIONS 00 le Rid Boe a Sees Leh Instruction Alignment and Checking 26 L 7 OPERAND PTERDS AND SUBELER
22. a header line like the following BEGIN XSNAP CALL AT CCAAAAAA USER REGISTERS is the number of calls made to XDUMP so far for identification CCAAAAAA shows the last 32 bits of the user s PSW in hexadecimal EC gives the ILC CC and Program Mask at the time of the XDUMP AAAAAA gives the address of the instruction following the XDUMP and thus can be used to distinguish between the output of different XDUMP statements NOTE XDUMP is the same as XDUMP with no operand STORAGE DUMP XDUMP area length Coding XDUMP with an address and length produces a dump of a user storage area beginning at the address given by area and ending at the address areatlength The operands are specified like those of XREAD XPRNT XPNCH except the length may not specify a register but must be an explicit length The resulting output includes a header line like the above followed by a hexadecimal and alphanumeric dump of the selected storage area The storage is printed in lines showing two groups of four fullwords preceded by the memory address of the first word in each line and followed by the alphanumeric representation of the 32 bytes on the line with letters numbers and blanks printed directly and all other characters translated to periods The storage printed is also preceded by a line giving the address limits specified in the XDUMP If the length is omitted the value 4 is used as a default
23. after th xecution of an XOPC 12 instruction as machine emulation in ASSIST defaults to S370 i e S370 instructions will be interpreted XOPC 14 SET INTERRUPT COUNT This instruction allows the user to halt program execution when the ASSIST instruction counter and the value found in register 0 become equal i e cause a COUNT INTERRUPT This instruction should be used in conjunction with the XOPC 11 instruction Any negative value found in user register 0 when this instruction is executed will disarm the count interrupt facility Example of Use The user desires a count interrupt to occur if 200 instructions are executed from this point on Note The ASSIST instruction counter counts down XOPC 11 Load register 0 with current instruction counter S RO F 200 decrement counter by 200 XOPC 14 Set interrupt count 200 instructions from now ASSIST4 7 XOPC 15 z SET COUNT EXIT ADDRESS The value found in user register 0 when this instruction is executed will be used as an exit address if a count interrupt occurs i e when th instruction counter becomes qual to the clock comparator see XOPC 14 If a count interrupt occurs after this instruction has been executed th psw at interrupt will be loaded into user registers 0 and 1 Execution will then continue beginning at the given exit address If no exit address has been specified and a count interrupt occurs the program abnormally te
24. combination of parameters DUMP This option controls the size of the dump printed on any error ermination during program execution If DUMP 0 a full dump is given t This includes a PSW completion code instruction trace general purpose a s nd floating point registers and all contents of the user program s torage area If DUMP 1 ASSIST omits the contents of user storage H REE ASSIST normally acquires the largest single block of space in its region for a dynamic workarea then releases part of that area back to the operating system for buffers and other uses The default is 4096 bytes returned but the value of FREE is used if supplied in case tape input or output is required or if extra space is required for the user program If the value of FREE is greater than the total obtained it is ignored and no space is returned x XNOTE THIS OPTION WILL PROBABLY BE NEEDED BY ANYONE USING BLOCKED INPUT FROM TAPE OR DISK Ls This parameter provides a limit on the number of instructions which which can be executed by the user program during its execution If this limit is exceeded during execution a message and a completion dump are printed This is th recommended and most economical way to prevent infinite loops during user program execution A limit for execution time may also be used to terminate loops TX KP KP 26 specifies that an
25. disabled the Boundary 10 XOPC 10 TURN OFF BOUNDARY ALIGNMENT CHECKING FACILITY ASSIST be allowed after th xecution of this This instruction disables Boundary Alignment checking in his implies that SOC6 Alignment Interrupts will no longer instruction Thus the user is no longer restricted by storage alignments and can fetch and store data on odd word boundaries ASSIST4 6 XOPC 11 F ti TCH ASSIST INSTRUCTION COUNTER The current value of the ASSIST Instruction Counter is put in user register 0 This instruction should be used in conjunction with the XOPC 14 instruction described below The instruction counter is put into the register in hexidecimal form XOPC 12 EMULATE SYSTEM 360 This instruction causes ASSIST to emulate a system 360 That is ASSIST will act as if it is running on an S360 no matter what machine S360 or S370 it is really running on It should be noted that emulation in ASSIST defaults to S370 S370 instructions will be interpreted After the execution of this instruction however ONLY S360 instructions will be interpreted S370 instructions will cause user program termination SOC1 XOPC 13 EMULATE SYSTEM 370 This instruction causes ASSIST to emulate a system 370 That is ASSIST will act as if it is running on an S370 no matter what machine S360 or S370 it is really running on This instruction should only be used
26. is provided for debugging purposes and contains the following items 1 ASSIST COMPLETION DUMP The above header begins the dump 2 PSW AT ABEND XXXXXXXX XXXXXXXX COMPLETION CODE typ cod messag This line gives the user s Program Status Word in hexadecimal followed by further information concerning the reason for termination The type given is one of the following a SYSTEM indicating that the code given is the same as that given by OS 360 such as for program interrupts b ASSIST indicating a completion code which does not necessarily correspond directly to a code used by 0S 360 The three digit hexadecimal code is followed by a descriptive message PART IV D provides a list of the messages and codes Sie x x TRACE OF INSTRUCTIONS JUST BEFORE TERMINATION PSW BITS SHOWN AR THOSE JUST BEFORE CORRESPONDING INSTRUCTIONS DECODED E IM LOCATION INSTRUCTION IM PSW BITS 32 39 ILC CC MASK BEFORE INSTRUCTION EXECUTED AT PROGRAM LOCATION SHOWN aa bbbbbb cece EEC cecc 1 10 lines in this format The above section in a dump lists up to the last ten instructions xecuted before termination with the last instruction shown usually causing the termination Parts aa and bbbbbb make up a user PSW in each line and are followed by from one to three halfwords of instruction represented by cccc
27. section AS114 INVALID CONSTANT A constant contains invalid characters for its type or is specified improperly in some other way AS115 INVALID DELIMITER The character flagged cannot appear in the statement where it does This message is used whenever the scanner expects a certain kind of delimiter to be used and it is not there AS116 INVALID FIELD The field flagged has an unrecognizable value or is otherwise incorrectly coded PRINT OF is flagged this way AS117 INVALID SYMBOL The symbol flagged either contains nine or more characters or does not begin with an alphabetic character as is required AS118 INVALID OP CODE The statement contains an unrecognizable mnemonic op code or none at all Note that different versions of ASSIST may not accept some of the possible op codes The first heading described in PART IV B 1l a describes which op codes are allowed AS119 PREVIOUSLY DEFINED SYMBOL The symbol in the label field has been previously used as a label or a SET variable has been previously declared AS120 ABSOLUTE EXPRESSION REQUIRED A relocatable expression is used where an absolute one is required such as in constant duplication factor or for a register AS121 ASSIST5 5 MISSING DELIMITER A delimiter is expected but not found For instance a C type AS122 AS123 AS124 AS126 constant code
28. symbol as a name and statements from different DSECT s may not be interspersed EXTERNAL DUMMY SECTIONS ASSEMBLER F ONLY External dummy sections are not supported so the commands CXD and DXD are not recognized COM DEFINE BLANK COMMON CONTROL SECTION COM is not allowed ASSIST1 7 SECTION 4 MACHINE INSTRUCTIONS H nstruction Alignment and Checking If any statement requires alignment and causes bytes to be skipped the bytes skipped are NOT necessarily set to hexadecimal zeros OPERAND FIELDS AND SUBFIELDS ASSIST permits the same use of expressions in machine instruction operand fields as does the standard assembler SECTION 5 ASSEMBLER LANGUAGE STATEMENTS OPSYN EQUATE OPERATION CODE is not accepted DC DEFINE CONSTANT Multiple operands up to 10 operands in a single DC statement and multiple constants within operands are both permitted Bytes skipped to align a DC statement are NOT zeroed Operand Subfield 3 Modifiers The following modifiers are not permitted by ASSIST Bit Length Specification Scale Modifier and Exponent Modifier Operand Subfield 4 Constant Fixed Point Constants F and H Fixed point constants may not contain decimal points or exponents While lengths may range from one to eight bytes the minimum and maximum values permitted are those for length 4 Floati
29. the symbols RO R15 being used for registers 0 15 In addition a second set exists which has more mnemonic meaning only symbolic registers in his program and should thus include any of The user is urged to utilize the required EQU instructions in his program In particular registers 7 11 should be coded using the symbols RA RE The additonal symbolic register equates are as follows RW EQU R3 GENERAL WORK REGISTER 1 RX EQU R4 GENERAL WORK REGISTER 2 RY EQU R6 GENERAL WORK REGISTER 3 RZ EQU R6 GENERAL WORK REGISTER 4 RA EQU R7 PARAMETER REGISTER 1 This register is commonly used as a scan pointer register inside the assembler RB EQU R8 PARAMETER REGISTER 2 This register is commonly used to pass a control value to a subroutine and on return almost always contains either an error code or a zero to show no errors RC EQU R9 PARAMETER REGISTER 3 This register is most often used in the assembler for passing a 24 bit value such as the result of an expression or a self defining term RD EQU R10 PARAMETER REGISTER 4 RE EQU R11 PARAMETER REGISTER 5 Registers RD and RE may be used for subroutines needing more than two or three argument
30. values of the parameter registers as returned by the user entry name ARO59 WARNING ERROR IN USER REGS error list If any of the user registers has an incorrect value this message is printed either following ARO50 or ARO58 depending on whether the incorrect value s were in a call to another module or in a return of values to the calling program The error list consists of one or more of the following RO R6 when a user program returned the values in registers 0 6 were not all the same as when it was called R12 the user program modified the value of the assembler table pointer which is not permitted R13 the user did not restor th sav area pointer 55555555 The dollar signs indicate a register shown in messages ARO50 or ARO58 as incorrect If this message appears RFLAG byte 1 bit 0 is set to 1 for the next time the user program is called AR100 REPLACE CSECT NOT FOUND REPLACE ABORT This message appears immediately after the assembly of the user program None of the allowable csect names were found as a Csect in the user program AR101 INVALID ENTRYPOINT NAME name CALLED REPLACE ACTION ABORTED If name appeared in an AROO2 message and is called this message appears followed by a dump of user storage and the last values of the user registers AR102 USER PROGRAM ABENDED DURING
31. with any page counting The parameters R and RX are used just as are P PX and PD with records substituted for pages One possible difference is in ASSIST systems with special record control type 2 s header description PART IV B 1l a In this case the initial record remaining count is also determined by the number of records actually left if this value can be obtained from the operating system This value is used rather than the default value if the user did not specify R on the EXEC card or JOB card As in Note B under P use RD 0 for replacement runs RD RD the number of output records reserved for a user completion dump It is used in conjunction with R and RX in the same way that PD is used with P and PX RD 0 is appropriate for well debugged programs and RD 25 is probably the most reasonable value for most runs as it saves enough for a partial dump under all conditions RELOC NORELOC Under NORELOC a user program is assembled with a location counter beginning either at 0 or the value on a start card and the program is executed as though it were actually loaded at whatever addresses are given on the assembly listing Maximum debugging checking is provided by this mode as the user may not branch store or fetch outside the area of his program RELOC in effect inserts a start card at the beginning of the source program which specifies the actual location in memory at which the user pr
32. 0 899 Execution is deleted if the total number of errors exceeds the NERR parameter as described in PART III These correspond to OS severity codes of 8 and 12 c Disastrous errors is in range 900 999 Some condition prevents successful completion of the assembly process Execution of the user program may or may not be permitted 3 LIST OF ASS CJ BLER ERROR The following lists the ASSIST5 2 MESSAGES codes and messages issued by the ASSIST assembler with further explanations following each message AS000 W ALIGNMENT ERROR IMPROPER BOUNDARY The address used in a machine instruction is not aligned to the correct boundary required by the type of instruction used AS001 W ENTRY ERROR CONFLICT OR UNDEFINED A symbol named in an ENTRY statement is either undefined or is also named in either a DSECT or EXTRN statement AS002 W EXTERNAL NAME ERROR OR CONFLICT A symbol named in an EXTRN statement is ither defined in the program or is named in an ENTRY statement AS003 W REGISTER NOT USED The register flagged in a DROP statement is not available for use as a base register at this point in the program This may be caused by an error in a USING statement naming the register AS004 W ODD REGISTER USED EVEN REQUIRED An odd register is coded in a machine instruction requiring t
33. 996 NO TXT CARD RECEIVED The loader encountered an end of file indication or ASSIST control card before finding any TXT cards xxx AT997 TXT CARD ADDRESS BELOW 1ST TXT CARD In order to perform relocation from TXT addresses to appropriate memory addresses no TXT card can have a lower address than the first one found This requirement was not met by the card displayed AT998 TXT CARD ADDRESS EXCEEDED STORAGE The area described in message AL000 was not sufficiently large to hold all of the object code i the address of at least one byte of code on the offending card was required to be beyond the end of the available space AT999 LOAD ABORTED This message follows any of th other messages to note the immediate termination of the loading process ASRE 3 0 June ASSIST ASSEMBLER REPLACEMENT USER S GUIDE Program amp Documentation John R Mashey Project Supervision Graham Campbell PSU Computer Science Department PREFACE This manual is the key referenc source for the pr uses the replacement facility of ASSIST This facility programmer to write and test his own versions of cer modules which are part of the ASSIST Assembler The m are replaceable perform a wide variety of functions thus a number of different course assignments covering import of a running 360 Assembler Among those replacable are management of the symbol table base register table covnve
34. ASSIST1 1 3 0 B ASSIST MARCH 1974 INTRODUCTORY ASSEMBLER USER S MANUAL Program amp Documentation John R Mashey Project Supervision Graham Campbell Computer Science Department Pennsylvania State University PREFACE This manual is the basic reference for the programmer writing in the Assembler Language for the IBM S 360 computer using the ASSIST assembler interpreter system ASSIST Assembler System for Student Instruction and Systems Teaching is a small high speed low overhead assembler interpreter system especially designed for use by students learning assembler language Th assembler program accepts a large subset of the standard Assembler Language under 0OS 360 and includes most common features The execution tim interpreter simulates the full 360 instruction set with complete checking for errors meaning ful diagnostics and completion dumps of much smaller size than the normal system dumps The first part of this manual describes th assembly language commands permitted by the ASSIST assembler In essence it is a comparison with the standard Assembly Language and generally notes only the omissions or differences from the standard The reader should refer to one of the following publications which the first part of this manual closely follows depending on operating system used C28 6514 IBM SYSTEM 360 OPERATING SYSTEM ASSEMBLER LANGUAG E
35. B RECFM FA LRECL 133 BLKSIZE DATA PAPER2 DD SYSOUT A DCB RECFM FA LRECL 133 BLKSIZE DATA CARD DD THIS STUFF IS READ AT THE SAME TIME AS ANOTHER FILE IS READ KKKKKK THE AST CARD KKKKKKK DATA INPUT DD THIS IS THE NORMAL INPUT FILE AND IS READ AT THE SAME TIME AS ANOTHER FILE IS READ KKKKKKKKK THE AST CARD KKKKKKKKK NOTE data a common usage for XG ET might be to access files of test ASSIST3 1 PART 111 ASSIST CONTROL CARDS AND DECK SETUP A JOB CONTROL LANGUAGE Depending on the type of ASSIST desired at a given installation one or two different types of deck setup can be used SINGLE RUN DECK SETUP NOBATCH This setup is suitable for individually submitted jobs and allows the most flexibility in job handling It is as follows a JOB card installation dependent EXEC ASACG SYSIN DD ee as 360 assembler source deck or ASSIST object deck DATA INPUT DD io data cards to be read by user program OANA UO BWNE If the programmer has no data to be read items 6 7 and _ 8 should be omitted The programmer specifies optional parameters by adding PARM option option after ASACG on the EXEC card BATCH RUN DECK SETUP This type of run is recommended if a number of jobs is to be given as a batch to ASSIST and is best for low overhead Each separate program in the batch must be set up as follows
36. CALL TO name REGISTERS RA RE values of regs 7 11 This message may be printed if the RFLAG byte 1 bit 3 is set and the user program calls some other ASSIST module It may also be printed if the user program tries to pass illegal parameter values to the routine name ASREPLGD 11 ARO51 ON ENTRY TO name STMT ADDR XXXXXX gt cardimage This message is printed before calling the user program and shows the current statement being processed if any The address of the cardimage is given by XXXXXX Which corresponds to the first character following the gt in the message The message is if RFLAG byte 1 bit 7 is set befor th call or if an error occurs in the user program ARO52 ON ENTRY TO name REGISTERS RA RE values of 5 registers This message displays the 5 parameter registers befor th user program name is called and is printed if RFLAG byte 1 bit 6 is on before the user program is called or if there is an error ARO54 ON EXIT FROM name REGISTERS RA RE values of 5 registers This message shows the correct values of the parameter registers as returned by the original ASSIST module name It is printed if RFLAG byte 1 bit 5 is on before call to the module or if the user program makes an error ARO58 ON EXIT FROM name REGISTERS RA RE values of 5 registers If RFLAG byte 1 bit 4 is on after completion of the user program or if there is an error this message appears and gives the
37. CMPRS The CMPRS option CoMPReSsed output produces an assembly listing which is approximately half as long as a standard listing This is done by removing the ADDR1 ADDR2 fields and printing only columns 1 40 of each statement While the listing produced is not as readable as the standard one this option is particularly recommended for remote terminal usage since programs are printed nearly twice as fast Tt does however increase the amount of dynamic storage required to run COMNT NOCOMNT The COMNT option causes the machine instructions of the program to be checked for the presence of comments 4 or more nonblank characters in the comment field If less than 80 percent of those statements have comments a message is printed and the program is not executed Some instructors may require this option on programs to be handed in and it is possible that some account numbers may imply this option whether the programmer codes it or not CPAGE NOCPAG If NOCPAGE is used no limits exist on the number of pages printed and lines are printed with whatever carriage controls are specified Coding CPAGE enables the usa of the following options L P PD PX SS SSD and SSX all of which are totally ignored otherwise Briefly a page may be declared to have a maximum number of lines L and limits given for the pages printed during various stages of a run The SS options then allow the maximum number of lines to be printed in a give
38. DO Sit na a ce 1 7 SECTION 5 ASSEMBLER LANGUAGE STATEMENTS o oooooooooooo o LJ tOPSYN TEQUATE OPERATION CODE g esige denise boat pibe LS DE DEFINE CONSTANT i septs sedate tare tina dia Neos ra is eli bey LS Operand Subfield 3 ModiflerS o oooooooooooooo oo ooo 1 7 Operand subfield 4 Costado ao 1 7 CCW DEFINE CHANNEL COMMAND WORD oo oooooo ooo 1 8 Listing Control INStEUCtETOnA Sica A a it ES 1 8 TITLE IDENTIFY ASSEMBLY QUTRUT s p len a os 1 8 PRINT BRENT OPTIONAL DATA aia aa ida ias a ans 1 8 PROGRAM CONTROL INSTRUCTIONS ee eo aceea ae aa ta ia 1 8 TCE TSEO PUNCH REPRO es 6 566 6 Site ta seve a eee ee ee e Es 1 8 LEORG BEGIN LITERAL POD T estos bini bb iene Robes it wage ee 1 8 Special Addressing Considerations ess cce eresie eseted 1 8 Duplicate LIS CIL da aa dede da cias de Teod acia de 1 8 COPY COPY PREDEFINED SOURCE CODING 1 8 SECTION 6 INTRODUCTION TO THE MACRO LANGUAGE 1 9 SECTION 7 HOW TO PREPARE MACRO DEFINITIONS 1 10 SECTION 8 HOW TO WRITE MACRO INSTRUCTIONS beo eei oeie paorder ens 1 10 SECTION 9 HOW TO WRITE CONDITIONAL ASSEMBLY INSTRUCTIONS 1 11 SECTION 10 EXTENDED FEATURES OF HE MACRO LANGUAGE L 12 ASSIST1 3
39. FRIENDLY ASSIST REPAIRMAN An internal error has occurred inside ASSIST Please send a deck AS230 INTERNAL CHAR BUFFER EXCEEDED Too much concatenation was done in the statement Remedy reduce the complexity of the statement AS231 MSTMG LIMIT EXCEEDED The MSTMG limit total number of statements processed during macro expansion has been exceeded a AS232 ZERO DIVIDE OR FIXED POINT OVERFLOW One of these interrupts was caused by the Use MSTMG to increase this statement given AS241 AS242 AS288 AS289 AS298 AS999 ASSIST5 9 SEQUENCE SYMBOL NOT FOUND This message immediately follows an AGO or successful AIF in open code whose sequence symbol could not be found before the END card As a result all of the program between the AIF AGO and END card is skipped over T BACKWARDS AIF AGO ILLEGAL This message appears following an AGO or successful AIF in the open code which references a previously defined sequence symbol ASSIST allows backwards branches only in macros not in open code ACRO XXXXXXXX COULD NOT BE FOUND This is issued by the macro library processor when it tries to get a macro and cannot find it in the library The macro may be named on a SYSLIB card or referenced by another macro UNABLE TO OPEN MACRO LIBRARY OPTION CANCELED This is issued after a SYSLIB card is encountered but the macro library cannot be
40. ION The XREPL instruction is an SI format instruction in which the immediate field is used to specify a type of action It is coded as XREPL ADDR CODE with CODE meaning as follows 0 set the RFLAG from the 2 byte area specified by ADDR 1 fetch the RFLAG into the 2 byte area specified by ADDR 2 fetch the number of instructions left into the 4 byte area given by ADDR This value is decremented each time an instruction is done The following gives an example of the use of XREPL XREPL MYRFLAG 1 get the value of the RFLAG TM MYRFLAG 1 128 was there an error last time BZ 12 no don t reset it OI MYRFLAG 1 8 4 2 1 set all these for debug output XREPL MYRFLAG 0 reset the RFLAG to new setting PART 111 JOB CONTROL LANGUAGE AND PARM OPTIONS A JOB CONTROL L The deck se a JOB CARD EXEC ASACG SYSIN DD ANGUAG Gl ASREPLGD 09 tup for a single job replacement run is as follows PARM REPL other options if any kre ake user writ END Reds a atte user tes ten replacement program end card of replacement program t deck for his replacement program The deck setup for a replace program run under BATCH is SJOB SENTRY B PARM OPTIONS The followi the user of the REPL requir just a RFLAG number e run ASSIST ACCT REPL other options user written replacement program if any
41. IST does the following Lo Scans the card adding any name found there to the list of macro names If the name is already in the list it is totally ignored 253 Scans the list of macro names If a macro is not defined it searches the macro library for it If the macro cannot be obtained it marks the macro searched for and never looks for it again 3 If the macro is found during 2 the print control is turned OFF unless the user specified LIBMC in which case the print control is unchanged The macro is then read and edited like a programmer macro 4 During step 3 the macro being read may refer to other macros not yet defined and these are added to the macro list also The loop of steps 2 3 4 continues until all macros in the list hav ither been found or searched for Thus it is possible for a reference to one macro to cause a number of macros to be fetched from the library At this point print control is restored to its original value and a list of undefined macros is produced The following gives the overall layout of a program Lag O or more programmer macro definitions with print control statements interspersed if desired TA 1 or more SYSLIB cards AN 0 or more GBLx declarations if open code cond asm allowed esr eae 0 or more LCLx declarations u PEE ACTR y os open code main body of program The following shows appropriate SYSLIB use although the program itself should not be e
42. NORED TEXT CARD 1 rey IGNORED 2 4 TXT 5 x 00 IGNORED 6 8 beginning address of text code which is on this card 9 10 blanks IGNORED 11 x 00 IGNORED 12 length of object code on card from X 00 to X 38 i e 0 to 56 decimal bytes of code 13 16 blanks IGNORED 17 72 up to 56 bytes of code to be loaded at given address 73 80 sequenc IGNORED Note that the format above resembles the standard given in IBM S 360 OS Assembler F Programmer s Guide GC26 3756 Appendix B When ASSIST punches an object deck it punches th ntir program storage including character 5 s which fill any DS or other areas not having specified code values Unlike the standard system assemblers ASSIST always punches an END card with an entry point address on it whether the user specifies an entry point on the source END card or not Although it is not possible to perform symbolic linkage of multiple decks it is possible to link multiple decks if the user assembles ach of several programs at particular locations known to each other using START cards Deck linkage can then be accomplished by locating a vector of address constants at the beginning of each assembly which can then be used to reference any required areas or modules within that assembly Note that this type of procedure will not work if RELOC is used ASSIST5 16 2 ASSIST LOADER USAGE AND MESSAGES T The ASSIST loader i
43. R ERROR MESSAGI The MNOTE statements accepted by ASSIST follow the standard but ASSIST effectively ignores the use of severity codes except that MNOTE S with numerical severity codes are printed as errors while ones with are printed in another format amp SYSECT Current Control Section CSECT or DSECT statements processed in a macro definition do NOT affect the value for amp SYSECT for any subsequent inner macros in that definition MACRO DEFINITION COMPATIBILITY ASSIST does not accept AGOB or AIFB APPENDIX K USE OF LIBRARY MACROS This section describes the deck layout and use of SYSLIB cards when the user desires to use macros from a system library Brief notes are given regarding internal workings of macro processing in order to help the requirements be more meaningful ASSIST performs all macro processing during the first pass of its total of two passes across the source program Macro processing itself has two stages During the EDIT stage macro definitions are read scanned and printed while tables are built in memory describing them The EXPANSION stage is part of the normal first pass of a two pass assembler so that every time a macro call is encountered the macro processor expands the call into 0 or more statements which then act as though they had been read in the normal way For best use of limited memory ASSIST requires that ALL EDITING be done be
44. RM9 ZZZZZZZZ X amp PARM9 A AST LINE Given this restriction it is best to place any positional parms early in the list if they may require long values needing continuation MODEL STATEMENTS Variable symbols MAY be used to generate PRINT and END operations If the open code feature is allowed they may also be used to generate calls to macros at the outer level but not inside macros COPY STAT E ENTS COPY statements are not allowed SECTION 8 HOW TO WRITE MACRO INSTRUCTIONS There are no changes from the IBM standard ASSIST1 11 SECTION 9 HOW TO WRITE CONDITIONAL ASSEMBLY INSTRUCTIONS All of the conditional assembly instructions may be used inside macros They may only be used outside if the version of ASSIST being used supports it and there are restrictions in that use in any case ATTRIBUTES ASSIST is a two pass assembler performing macro processing on the fly during pass 1 As such it is impossible for it to usually know the attributes of a symbol so ther ar definit restrictions In effect the only attributes are those which can be found by looking Just at a macro call statement by itself The attributes allowed are Attribute Notation Type T only values N O and U possible Count K Number N Thus Length L Scaling S and Integer CE attributes are not supported The only values for Type are N Numeric O O
45. SIST SYSTEM PROGRAM LOGIC MANUAL ace Monito ar to the it may be required the entire register and g facilities ol Language printed by ing manual required to r messages above one necessary to information ASREPLGD 02 TABLE PART I THE ASSIST REPLACEMENT PROCESS A OVERVIEW OF THE ASSIST ASSE B STEPS IN THE REPLACEMENT PROCESS C REGISTE R AND SUBROUTINE LINKAGE CONVENTIONS PART Il REE As HE RFLAG B THE XREP zj U E D Q zj ONITOR DEBUGGING AIDS PART III JOB CONTROL LANGUAGE AND PARM OPTIONS oooooooooooooo A JOB CONTROL LANGUAGE FOR REPLACE RUN ooooooooooooo ooo ooo Bi PARM OPTION Saa sane dame PART IV REPLACE MONITOR MESSAGES ASREPLGD 03 PART I THE ASSIST REPLACEMENT PROC E n un A OVERVIEW OF THE ASSIST ASSEMBLER The ASSIST Assembler is a section of the entire ASSIST System which translates a deck of S 360 Assembler Language statements into object code in memory It is made up of approximately 30 control sections of which 3 are main control programs The overall control program is named MPCONO which calls the main programs for each of the two passes in the assembler and also calls all initialzation and termination entrypoints for the various other modul
46. SS 1 The programmer writes one control section which is to be assembled and used as a replacement for the existing one in ASSIST of the same name This control section must have the following characteristics a The CSECT and ENTRY names if any must be defined and spelled exactly as the existing ones b Certain replacable modules such as EVALUT are permitted to call existing ASSIST modules Any module so called can be done so by listing the module name in an EXTRN statement then referencing the module name by use of a V type address constant 2 After the user program is assembled and loaded into memory the Replace Monitor searches its list of replaceable control sections for one defined as a csect in the user program Th required ntry point names are found if possible in the user program During this process the Replace Monitor modifies certain address constants in the main control table of the assembler which will permit it to regain control every time one of the replaced entry points is called The messages labeled AROOO AROO1 and AROO2 may appear on the listing at this point If it cannot find a legally replaceable csect name th message AR100 is printed and the replacement process terminated The latter can also occur if the user program contains more serious errors than given by the value of the NERR parameter 3 VArious functions are performed to init
47. SSIST permit system macros to be used in addition to programmer written macros This facility requires the use of a special comment card SYSLIB as described later OPEN CODE CONDITIONAL ASSEMBLY system assemblers allow the user to use conditional assembly statements and SET variables outside macros i e in the open code or main body of the program With certain restrictions as noted this facility can be supplied if desired Finally in order to use macros at all the user must supply the parameter ACRO as described in Part III THE MACRO DEFINITION T COPY statements are not allowed 3 THE MACRO LIBRARY Certain restrictions exist in ASSIST s processing of system macros One or more SYSLIB cards must follow any programmer defined macro definitions These cards indicate that library search is required and must name any macros which are called from the open code later but have not been previously mentioned in the programmer written macros The user should consult the appendix USE OF LIBRARY MACROS in this PART SYSTEM AND PROGRAMMER MACRO DEFINITIONS Since ASSIST reads in system macros and edits them upon command of SYSLIB cards immediately following programmer macros they are treated exactly the same as programmer macros except that they are not printed unless requested by the LIBMC option Errors are attached to correct statements ASSI
48. ST1 10 SECTION 7 HOW TO PREPARE MACRO DEFINITIONS MACRO INSTRUCTION PROTOTYP ira Two formats are allowed for statements the normal one used by all other statements and the alternate one allowed only for macro prototype and macro call statements ASSIST does allow macro prototypes and macro calls to be continued on an indefinite number of cards When ther ar no more than 2 continuation cards ASSIST is completely compatible with other assemblers If the total number of cards in a statement exceeds 3 the following restriction must be followed every third card in the statement must use the alternate format unless it is the last one This is done because ASSIST processes cards in groups of 3 The two prototypes below illustrate this restriction PROTOTYPE ACCEPTED BY ASSEMBLERS F G H VS BUT NOT ASSIST amp LABEL LONGPROT amp PARM1 amp PARM2 PARMS ALTERNATE FORMA X amp PARM3 amp PARM4 amp PARM5 PARMS ALTERNATE FORMA X amp PARM6 amp PARM7 XXXXXXXX amp PARM8 YYYYYYYY amp PARM9 ZZZZZZZZ amp X PARM9 A AST LINE EQUIVALENT PROTOTYPE ACCEPTED BY ASSIST amp LABEL LONGPROT amp PARM1 amp PARM2 PARMS ALTERNATE FORMA X amp PARM3 amp PARM4 amp PARM5 PARMS ALTERNATE FORMA X amp PARM6 amp PARM7 XXXXXXXX amp PARM8 YYYYYYYY amp PA
49. X RUN TIME RELOCATION xx This message is printed at the e ASSIST5 17 loader are of the form AL AT xxxxxx USABLE CORE ENDS AT oading is begun and gives the Can be loaded and the address of Th ntir area mentioned is ing is begun ESSES LOW xxxxxx HIGH XXXXXX XRRR EER nd of a successful load It gives the low and high addresses in user r lativ her values as found in incoming TXT cards the entry point address w xecution is to begin again in user relative terms and the run time relocation factor This last value is used during interpretiv x program defined address to obtain an far as the user program is concerned LOW and HIGH addresses given If REL will be set to zero regardless of th to load the program cution and is added to every actual address in memory i e as it is actually located between th OC is used the relocation factor e relocation factor actually used The following messages indicate a error in the input deck Loading is terminated and user program execution does not occur EXNOTE F gt dE ither message AL997 or AL998 appears it will be followed by an XSNAP labeled IMAGE OF INCORRECT OBJECT CARD and the offending card displayed beginning at the first address given by the XSNAP AL
50. XECUTION BEGINNING ANY OUTPUT BEFOR MESSAGE IS PRODUCED BY USER PROGRAM This message is issued immediately befor th user program is executed and serves to delimit user output CJ EXECUTION TIM Gl d EXECUTION TIME SECONDS INSTRUCTIONS EXECUTED HH HH INSTRUCTIONS SEC FIRST CARD NOT READ card image This message is issued immediately after the user program has been executed and supplies statistics regarding the execution time and rate of execution of the user program The time shown may be slightly smaller than the actual time if the completion code given in the dump is ASSIST 223 TIME LIMIT EXCEEDED The second part appears if one or more data cards were not read by the user program e TOTAL RUN TIME UNDER ASSIST SECS This is the last line printed by ASSIST and th tim given includes time for the entire run Printed only if CHECK TRP 2 2 AM001 ASSIST COULD NOT OPEN PRINTER F AM002 AM003 AMO004 AM005 ASSIST MONITOR ERROR MESSAGES The ASSIST monitor may also issue any of which are of the form AM and usual ASSIST5 12 the following messages Lly indicate errors 06F001 ABORT This message appears in th ASSIST is unable to open the DCB F i nc
51. a specific set of file names which can differ from installation to installation It is advisable to check on local procedures The instructions are coded as follows label xmacro area length label is an optional statement label xmacro is either XGET or XPUT area is the address in memory to be read or written This area may be specified by an RX type address i e anything legal as the second operand of a LA instruction such as 0 1 2 AREA2 10 card 1 3 or CL30 0 MESSAGE length specifies the number of bytes to be read or written This length can range from 1 to the maximum length for the appropriate device 80 for cards 133 for printer etc The length field must not be omitted it may also be specified as a register enclosed in parentheses indicating that the length will be supplied at execution time from the designated register If during execution the length has a value of zero the file will be closed NOTE During execution register 1 must point to an eight byte character string which is the name of the file to be manipulated CONDITION COD EJ XGET and XPUT both change the condition code as follows CcC 0 normal input output occurred CC 1 XGET ONLY end of file occurred CC 2 shows an error like invalid data address which causes S individual operation to be ignored CC 3 shows that the file could not b opened becaus it is WwW t
52. abbreviation for th actually printed by ASSIST in the form STMT MA AS221 ACTR COUNTER The ACTR count option or by a EXCEEDED has been exceeded n ACTR statement The ACT This ind rror found during the Some messages also add script Note that the e actual output which is CRO name Ris set by the MACTR icates a looping macro AS222 INVALID SYM PAR OR SET SYMBOL SUBSCRIPT gt value A subscript is out of range The offending value is given AS223 SUBSTRING EXPRESSION OUT OF RANGE gt value This is most often caused by the first subscript in a substring expression having a nonpositive value or one larger than the size of the string AS224 INVALID CONVERSION CHAR TO ARITH gt value The value could not be converted to arithmetic form AS225 INVALID CONVERSION ARITH TO BOOLEAN gt value The value was not 0 or 1 AS226 INVALID CONVERSION CHAR TO BOOLEAN gt value The value was not 0 or 1 so it could not be converted AS227 ILLEGAL ATTRIBUTE USE An attribute was used incorrectly AS228 amp SYSLIST SUBSCRIPT OUT OF RANGE The subscript has a value greater than the maximum number of fields which can be supplied AS229 CALL
53. all is checked to see if it is a legitamate one If so the parameter registers may be printed ARO50 and then checked to make sure they contain legal values If they are illegal for any reason they are flagged with message ARO59 the user program is dumped and no further calls are made to user entry points If the call is legal the desired routine is called and its parameter values placed in the user s registers and step 6 is begun once more 9 Finally the assembly of the test program is completed with all calls having been made to the appropriate entry points of the user replacement program Messages AR003 and AROO4 are then printed giving various statistics about the performace of the user program These include the number of times each entry point was called the total number of instructions executed by each entry the number of times the values returned by the user program were incorrect the average number of instructions executed per call and the percent of the calls which were handled incorrectly 10 If the option BATCH was specified control returns to step 1 thus allowing different modules to be tested during one run Otherwise ASSIST execution terminates C REGISTI 1 REGISTER USAGE T T ASREPLGD 06 ER AND SUBROUTINE LINKAGE CONVENTIONS The general purpose registers are referred to by two separate sets of symbols The first is a set of absolut register quates
54. d with no ending is flagged this way FEATURE NOT CURRENTLY IMPLEMENTED he version of ASSIST being used does not support the language feature used ISSING OPERAND The instruction requires an operand but it is not specified ABEL REQUIRED An instruction requiring a label such as a DSECT is coded without one RELOCATABLE EXPRESSION REQUIRED An absolute expression or term is used where a relocatable one is required by ASSIST such as in the first operand of a USING Also this message may appear if the final relocatiblity attribute of the value in an address constant is that of a symbol in a DSECT AS127 INVALID SELF DEFINING TERM The self defining term flagged contains an illegal character for its type has a value too large for 24 bits to contain or is otherwise incorrectly specified AS128 ILLEGAL START CARD The START card flagged is coded with one or more statements other than listing controls or comments appearing before it AS129 ILLEGAL USE OF LITERAL The literal constant appears in the receiving field of an instruction which modifies storage e g ST 0 F 1 AS130 UNDEFINED SYMBOL The symbol shown is either completely undefined or has not been already defined when it is required to be Symbols used in ORG instructions or in constant lengths or duplication factors must be d
55. deck is given in PART IV E 1 The ASSIST loader reads the object deck until an end of file or ASSIST control card is found producing an object program in memory which is then treated exactly as though the source program had been just assembled there The loader also issues various messages of the form AL which are explained in PART IV E 2 The user should read all of PART IV E before using the OBJIN option sinc ther ar a number of restrictions which must be noted befor using object decks as input to ASSIST In general a single ASSIST produced deck should almost always be workable a single deck produced by the standard system assembler or multiple decks of any sort may be usable if they were created following certain conventions Decks requiring symbolic linkage among control sections will definitely NOT run correctly ASSIST3 7 This gives the maximum number of pages with L lines per page which are permitted for a complete job or from one S JOB card to the next if BATCH is used It is only meaningful if CPAGE is on The entire process of page counting which also involves values of PD and PX is summarized as follows 1 As described in PART III B the value of P is calculated before ASSIST prints anything for the job ASSIST prints the beginning of the header line followed by the PARM field or the SJOB card and then assembly begins If the p value is exceeded
56. during assembly the job is halted at that point 2 If the user program assembles successfully and is to be executed a page limit is calculated for execution plus dump The total for these two phases is set to the minimum of the PX option and the number of pages remaining from before 3 A temporary limit for user program execution alone is calculated by subtracting the value of the PD option thus reserving that number of pages for a dump User program execution occurs and may be terminated if the temporary page limit is exceeded 4 After execution the PD value is added to the current pages remaining counter and the dump begun The dump continues until it is completed or it runs out of pages Note A At steps 3 and 4 the lines remaining count is just carried forward so that the user gets the benefit of any partial pages Note B For REPL runs assembler replacement step thr is performed twice once for the replacement program and once for the program it assembles if execution is desired for it Since a dump of the replacement program does not occur during the user dump phase it is recommended that no pages be saved for it i e PD 0 Note C Any process which can be halted by exceeding page count can also be halted by exceeding record limits see R or time limits see T and for user program execution exceeding instruction count limit see I PD This option specifie
57. e SSX during user program execution and SSD during a completion dump The carriage control conversions are as follows 1 page skip becomes 0 overprinting remains triple space becomes single space remains J O double space becomes any other character becomes r SSD NOSSD SSD is the SS option during completion dump see SS above Using SSD allows a partial dump plus 1K of storage to be printed on 1 page SSX NOSSX SSX is the SS option during user execution see SS above T This gives a limit in seconds on the total time allowed for a run The handling of the three time limits T TX and TD is exactly analogous to that for pages see P and records limits The values are coded as integer values of seconds or with fractional values up to three digits thus allowing for millisecond specifications As shown in Note B under P TD 0 should be used for replacement runs The appropriate times used depend on the model of machine being used with the following times being appropriate for student runs on a 360 65 T H5 TX 5 TD 1 Some versions of ASSIST may contain NO timing code at all option 0 and some may contain special option 2 In the latter case ASSIST obtains a time remaining estimate from the operating system and uses it rather than the default if the user specifies no time limit himself The user may examine the ASSIST header to determine wh
58. e is done 2 The address in register 1 is used as the address wher normal execution of the user program will resume If register 1 is not modified in the interrupt processing code execution of the user program will continue with the instruction immediately following the instruction that caused the initial interrupt Otherwise the user will be expected to load register 1 with an appropriate address 3 User registers 0 and 1 are reloaded with the values they had when the initial interrupt occurred 4 Normal execution of the user program is resumed with the user no longer in the INTERRUPT PROCESSING STATE XOPC 22 DUMP TH INSTRUCTION EXECUTION COUNT FACILITY STATISTICS ira This instruction prints out a statistical report according to address of the number of instructions counted within the specified limit addresses by the Instruction Execution Count Facility An instruction executed 0 times will cause no statistical line to be printed Groups of instructions executed the same number of times will produce one statistical line This shows th user wher his major loops are and where most of his execution time is being spent If this instruction is executed and the count facility has not yet been nabled at least once in the user program i e no count space has been allocated the condition code of the user program is set to one and this instruction is ignored As an example consider the fo
59. e the modify and fetch bits for the SR flag Possible values for lt M gt and lt F gt are O turn bit off T turn bit on e leave bit in previous state If an lt F gt specification is omitted this is equivalent to a It is suggested that the user begin by just specifying XREF 2 or 3 and then cutting out unnecessary references later Although complex the facilities allow unwanted output to easily be eliminated The following gives as example assumed to be a large program XREF SD 10 following symbols will have only modify refs large number of DS and DC statements global table for example XREF SD 1 add modify and fetch references both more symbols in DSECTS tables etc XREF SD 00 SR 10 collect no references to symbols defined from here on collect modify references created section of code referencing tables above XREF SD 11 SR 11 collect all references from following code to 2nd part of table modify references to first part and all references to itself On section of code referencing tables ASSIST4 1 PART IV ASSIST OPTIONAL EXTENDED INTERPRETER A DESCRITPION OF NEW FEATURES The ASSIST Optional Extended Interpreter is a seperate control section which can replace the original ASSIST interpreter if certain additional program debugging features ar desired These features include additional pseudo instruction
60. ected across any calling sequence and must be restored if changed R14 RET must also be restored if changed before returning b Register R12 RAT may not be changed by any routine c Registers R R11 RA RE are used for parameters and temporary work registers and are not protected at all across calls No routine ver requires more than five arguments so thes fiv registers are sufficient d Except for the above all normal OS 360 conventions are followed regarding save area linkage requirements and usage In general most routine only save as many registers as required Lowest level routines use R15 as a base and do not perfrom save area linkage other routines usually use R13 as a base and save area pointer e For replacement runs the user must include any needed EQU symbols for registers Note that all documentation and output produced by the Replace Monitor refers to registers 7 11 as RA RE so that using these symbols in a replacement program will aid reading the various diagnostic output produced ASREPLGD 08 PART II REPLACE MONITOR DEBUGGING AIDS A THE RFLAG Communication between the user program and the Replace Monitor is achieved through the use of the User Replace Flag called the RFLAG This is a two byte area of storage which may initialized for an entire run using the RFLAG option in the PARM field Certain bits in it determine which diagnostic messa
61. efined before they are used ASSIST5 6 AS131 UNRESOLVED EXTERNAL REFERENCE The symbol used in a V type constant is not defined in the assembly or is defined but not declared a CSECT or ENTRY ASSIST does not link multiple assemblies so this is an error AS132 ILLEGAL CHARACTER The character flagged is either not in the set of acceptable characters or is used in an illegal way AS133 TOO MANY PARENTHESIS LEVELS Parentheses are nested more than five deep in an expression AS134 RELOCATABLE EXPRESSION USED WITH OR RElocatable terms or expressions may not be used with either of these operators AS135 SYNTAX The character flagged is improperly used This catchall message is given by the general expression evaluator when it does not find what is expected during a scan AS136 TOO MANY TERMS IN EXPRESSION The expression contains more than the legal maximum of 16 terms AS137 UNEXPECTED END OF EXPRESSION The expression terminates without having enough closing parentheses to balance the opening ones used THE FOLLOWING MESSAG AS201 OPI ERAN During macro expansion positio ES ARE ONLY D NOT AL LOWED nal beyo an nd t AS202 STAT example order AS203 SI EMEN ete ET SYMBOL DIM A dimensioned set symbol was used without a dimension OUT
62. ely XOPC 18 SET ADDRESSES AND TURN ON THE IECE This instruction combines the actions of XOPC instructions 16 and 17 Register usage is assumed to be the same as in XOPC 17 XOPC 19 TURN OFF THE INSTRUCTION EXECUTION COUNT FACILITY This instruction disables the IECF This instruction will not have any effect on the IECF counting area ASSIST4 8 INSTRUCTION EXECUTION COUNT FACILITY XOPC 20 CLEAR TH COUNTING AR a ae a A This instruction resets the Instruction Execution Count Facility Counting area to zero If the IECF has never been nabled in the user program i e no counting space has been allocated the condition code of the user program is set to 1 and this instruction is ignored This instruction can be executed an unlimited number of times to insure accurate instruction counting Please note that the counter for each instruction is only a halfword 2 bytes in length Executing one instruction many times could overflow that counter and reset it to zero E XOPC 21 RETURN FROM INTERRUPT PROCESSING COD This instruction tells ASSIST that the User Program has com pleted any interrupt processing routine s and is ready to resume normal execution of the user program It causes the following actions to occur 1 If the user is not in the interrupt processing state the condition code is set to 1 and nothing mor
63. er is essen tially the same as that produced by the standard OS 360 assemblers with the following minor differences a Error messages are not printed at the end of the assembly listing but are printed after th ach statement causing the messages A scan pointer indicates the column where the error was discovered b No more than four messages are printed for any single source statement Some errors Cause termination of statement scan and errors following in the same statement may not be discovered However an error in a statement does not normally prevent its statement label from being defined which is usually the case with the standard assembler Cc As noted under PRINT in PART I and under NOLIST in PART III statements flagged are printed regardless of print status at the time d As noted under PRINT in PART I no more than eight bytes of data are printed for a statement even if PRINT DATA is used 2 ASSEMBLER ERROR MESSAGES The assembler produces error messages consisting of an error code followed by an error description The code is of the form AS with the value of indicating one of thr types of errors a Warnings is in range 000 099 These never prevent the execution of the program correspond to OS severity code 4 and e have messages beginning with characters W b Errors is in range 10
64. erpreted to prevent it from damaging any part of ASSIST The user program may thus access storage outside its area but may not modify such storage ASREPLGD 05 6 The user program is interpreted until it either terminates normally by returning to the return address supplied to it in R14 or terminates with some error 7 If the user program terminated normally the register values it returned are checked against the ones returned by the original module In some cases th xact register values do not matter but any value definitely wrong is noted If anything is actually wrong any debug information not already printed during step 4 is printed now Then the values of the user returned parameter registers are printed ARO58 followed by a message flagging the incorrect registers ARO59 The ARO58 message may be printed in any case if the appropriate bit in the current value of the user RFLAG is turned on Another bit in the RFLAG is set if an error has occurred This bit may be tested by the user program the next time it is called The correct values are placed in the parameter registers and control is returned to the program which originally called th replaced entry point 8 If the user program did not terminate normally and the error was a branch out of the user program it may be the case that the user program was attempting to call some other original ASSIST module The c
65. es in the assembler During the first pass under control of MOCON1 each card in the input source deck is read scanned for label and opcode and processed partially according to the type of opcode Each statement is given a location counter value during this pass and some types of statements are completely processed such as EQU START ORG etc Each cardimage and its associated information is then saved into a large dynamic workarea until an END card is encountered During the second pass each statement saved in the dynamic area is retrieved and processed Several different routines control the scanning of each statement and production of object code from it Each statement s object code if any is loaded into memory and the statement printed Approximately half of the modules of the assembler can be replaced using the ASSIST Replace Monitor In general these modules are those which are fairly low level routines which are not required to have communication with many other modules and which generally do not have to be able to examine variables and flags global to the entire assembler They definitely are never required to modify storage outside the limits of their own storage These characteristics make it possible for them to be replaced without requiring a great deal of knowledge of the internal workings of the ASSIST Assembler ASREPLGD 04 B STEPS IN THE REPLACEMENT PROCE
66. f OUT is a blank for carriage control XDECO 4 0UT convert the number XPRNT OUT 12 print value ac other assembler statments OUT DS CL12 typical output area ASSIST2 6 HEXADECIMAL CONVERSION INSTRUCTIONS XHEXI XHEXO NOTE Some versions of ASSIST may not provide these instructions XHEXI and XHEXO provide easy conversion of hexadecimal numbers for input and output The value of a hexadecimal number can be read from a card using XREAD converted from character mode to a hexadecimal number and the converted number is placed in the specified general purpose register with XHEXI XHEXO provides an easy way to convert internal hexadecimal to an output form that can be printed using XPRNT XHEXI also places the address of the first non hexadecimal number in register one but if more than eight digits are scanned the address of the ninth is placed in register 1 XHEXI XHEXI REGISTER ADDRESS XHEXI in the general form shown above where REGISTER is any general purpose register and ADDRESS is anything legal in an RX instruction is used to do the following 1 Beginning at the location ADDRESS memory is scanned until the first non blank character is found 2 If the first character found is anything but a legal hexa decimal character 0 9 A F the condition code is set to overflow and this address is placed in register 1 If t
67. fore ANY EXPANSION During editing of programmer macros a list is kept of opcodes not yet defined and thes ar presumed to be system macros Any system macros called by programmer macros are therefore known to ASSIST and so it can fetch them from the library However if a system macro is only called at in the open code ther is no way for ASSIST to know that it will be needed later Also ie ass desirable that the user specify whether the macro library should be searched at all in order to avoid searching the library for a mispelled opcode name automatically Thus a special comments card SYSLIB is used to inform assist that it should actually perform library search The format of the SYSLIB card is either of the following SYSLIB namel name2 comment s SYSLIB The first form gives a list of 1 or more macro names seprated by commas free format The second form contains no operands at all ASSIST1 13 The second form may be used only when all library macros appear in the user s macro definitions The SYSLIB card should follow all programmer macros if any and must precede any of the statements of the open code except for comment and listing control PRINT TITLE EJECT SPACE statements The user may supply 1 or more SYSLIB cards as long as these conditions are fulfilled thus allowing some convenienc When finding any SYSLIB card in a proper location ASS
68. found then the address found on the first TXT card d The user program cannot modify storage beyond the last code address so if it requires more work space it can specify a TXT card with zero length and a high enough address to reserve space Within the limits above TXT addresses can occur in any order and END cards can appear anywhere including the first card of the deck The user is cautioned to be careful in using the RELOC option with OBJIN ASSIST normally computes a relocation factor used to load the code which is equal to the lowest actual memory address minus the first TXT address After loading the code if RELOC is used the relocation is set to 0 since RELOC type programs must be run with no execution time relocation so they can reference low core addresses for instance Thus any deck to be run under RELOC should contain no relocatable type address constants of any type or else should use a START card to create the same addresses as where the program will be run which may be hard to do under general OS MFT and MVT systems essages produced by the ASSIST and include the following messages a xxx ATOOO ASSIST LOADER BEGINS LOAD XXXXXX This message is printed before 1 beginning real address at which code the first byte beyond the usable area filled with character 5 s before load xxx AT100 LOAD COMPLETED USER ADDR ENTRY XXXXX
69. ge control B READLOOP go back for next card to be read NOMORE EQU K branch here when no more cards EEE S more program statements DC Evo carriage control for printing card right before CARD CARD DS CL80 space for card to be read in The following statements show how the programmer may easily produce messages and headings for his output using XPRNT with literal character constants or related methods XPRNT CL30 1 A HEADING FOR NEW PAGE 30 XPRNT CL50 SECOND HEADING IMMEDIATELY UNDER FIRST 50 XPRNT MSG L MSG LET ASSEMBLER COMPUTE LENGTH XPRNT MSGX MSGXL ASSEMBLER COMPUTES LENGTH WITH EQU MSG DC C 0 THIRD MESSAGE SINGLE CONSTANT WITH LENGTH MSGX DC C FOURTH MESSAGE WHICH INCLUDES A SECTION FILLED IN DC C DURING EXECUTION MSGNMBR DS CL12 SPACE FOR DECIMAL NUMBER XDECO DC C END OF IT MSGXL EQU MSGX MSGXL IS SET TO LENGTH OF MESSAGE ASSIST2 3 DEBUGGING INSTRUCTION XDUMP One basic debugging command is provided called XDUMP It can be used in two different ways to print ither registers or storage areas GENERAL PURPOSE REGISTER DUMP XDUMP Coding XDUMP with no operands prints the contents of the user s general purpose registers in hexadecimal notation The registers are preceded by
70. ge is indicated by the value of as follows 000 049 informative or warning messages 050 099 debugging output messages produced during intercepted call 100 199 sever rror message causing replacement interception to end AROOO REPLACE CSECT name This message appears immediately after the replace csect has been assembled with name being the name of the replacing csect AROO1 REPLACE ENTRY name AT LOCATION xxxxxx If message AROOO appears each properly defined entry point in the csect will be listed here with its location xxxxxx in memory Note t hat a csect which can be entered through its csect name is also listed AR002 REPLACE ENTRY name NOT FOUND AS CSECT OR ti ENTRY his message may appear with the AR000 and AR001 messages for any entry or csect name which is required but either not defined in the user program or not declared as CSECT or ENTRY If this entry name is called during execution its execution will be terminated with an AR101 message and storage dump AR003 STATISTICS INSTRUCTIONS CALLS WRONG INSTRS CALL WRONG This message appears after the test program is assembled AR004 name 5 decimal numbers One of this message appears for each entry point after AR003 It describes the performance of the named entry point during the run AR050 ON
71. ges th Replac Monitor prints when it intercepts a call to a replaced module These bits can also be changed by the user program during execution thus allowing the user to obtain additional information when needed The various bits of the RFLAG are used as described in the table below BYTE BITS DECIMAL BINARY MEANING IF BIT ON AR MESSAGE 0 0 7 currently unused user can set or test for his own purposes L Af 1 00000001 print current statement on entry ARO51 6 2 00000010 print registers RA RE on entry ARO52 5 4 00000100 print correct regs RA RE on exit ARO54 from original ASSIST module 4 8 00001000 print registers RA RE on exit from ARO58 user replacement module 3 16 00010000 print registers RA RE if user AR050 module calls an original ASSIST module LZ 64 32 01100000 reserved for future use 0 128 10000000 is set to 1 when there is an error ARO59 parameter registers returned by the user program Is set to 0 if acceptable Bit 0 of byte 1 can be used to start extra debugging output only after an error occurs See the XREPL example for this action The entire first byte is reserved for the user program such as for additional debugging flag bits for controling the program Note that bits 5 6 7 ar tested befor th call to the user program Thus changing them affects output beginning at the next call to a user module B THE XREPL INSTRUCT
72. h to the return address originally supplied to the user program in register 14 ASSIST5 15 T E OBJECT DECKS AND LOADER MESSAGES 1 OBJECT DECK FORMAT ASSIST provides basic facilties for reading OBJIN and punching DECK object decks which whose format is a compatible subset of normal S 360 decks However ASSIST does not punch External Symbol Dictionary ESD or Relocation Dictionary RLD cards and ignores them if reading a deck Thus it cannot perform symbolic linkage between modules or relocate individual address constants The facility can be useful for saving assembler utility programs or for providing efficient running and good diagnostics for object code from student written compilers Two types of cards are punched and recognized text cards TXT which supply actual object code and end cards END which supply an optional entry point address for beginning of execution The formats of these cards are described below ALWAYS lists the characters which are defintely present DECK notes those which are punched and OBJIN those required for input The notation IGNORED means that the given card columns are completely ignored when loading an object deck CARD COLUMNS ALWAYS DECK OBJIN END CARD dl En IGNORED 2 4 END 5 x 00 IGNORED 6 8 entry address entry address or blanks 972 blank IGNORED 73 80 sequenc IG
73. he use of an even register for a specific operand Instructions which may flagged are Multiply Divide Double Shifts and all floating point instructions AS005 W END CARD MISSING SUPPLIED The assembler creates an END card becaus th user has supplied none before an end file marker ASSIST5 3 AS100 ADDRESSIBILITY ERROR An implied address is used which cannot be resolved into base displacement form No base register is available having the same relocatability attribute and a value from 0 to 4095 less than the value of the implied address AS101 CONSTANT TOO LONG Too many characters are coded for the type of constant specified This message appears if a literal constant contains more than 112 characters including the equals sign and delimiters AS102 ILLEGAL CONSTANT TYPE An unrecognizable type of constant is specified AS103 CONTINUATION CARD COLS 1 15 NONBLANK A continuation card contains nonblank characters in columns 1 15 This may be caused by an accidental punch in column 72 of the preceding card AS104 MORE THAN 2 CONTINUATION CARDS Three or more continuation cards are used which is illegal except on macro prototype statements and macro calls AS105 COMPLEX RELOCATABILITY ILLEGAL ASSIST does not permit complex relocatible expressions AS106 TOO MANY OPERANDS IN DC ASSIST allows no more than ten operands in a DC statement AS107 MAY NOT RESUME
74. he REGISTER is anything but register 1 its contents remain unchanged 3 One to eight hexadecimal characters are scanned the number converted to hexadecimal and the result is placed in REGISTER The value placed in the register is internal hexadecimal with leading zeros included and the number is right justified 4 Register one is set to the address of the first non hexadecimal character With this in mind the user should not code register one as REGISTER This allows you to scan across the card for any number of character strings The strings should be separated by blanks The end of the string could be flagged with any non hexadecimal character anda test could be made after a Branch Overflow see sample program 5 If more than eight hex digits are found register one is set to the address of the ninth This allows the user to scan across long strings of numbers XHEXO XHEXO REGISTER ADDRESS XHEXO in the general form shown above converts the value in REGISTER and places it in a right Jjustified 8 byte field beginning at ADDRESS It can be easily printed using an XPRNT instruction The XHEXO instruction modifies NO registers Mt number hen converted for output using XH numbers o after the last Y O Zo D Q za x XE PHVTtOD Pp NX XXE E x WwW aw OU E NUMBI
75. he following program segment reads a card and converts one decimal value of 1 9 digits punched anywhere on the card placing this value in general register RO XREAD CARD read card into a workarea XDECI RO CARD scan and convert the number XDECI can be used to convert an unknown number of decimal values from a card This can be done by punching the values anywhere on the card separated by one or more blanks The last number on the card is then followed by a which indicates the end of the data values to the program The following program reads a card and converts numbers storing their values in an array for later use and stopping when the is found SR 252 zero for index to first word of NUMBERS XREAD CARD read cardimage into input area LA 1 CARD intialize Rl as scan pointer register LOOP XDECI 0 0 1 scan and convert next number BO OVER skip if bad number of BC 1 OVER ST 0 NUMBERS 2 store legal value into array LA 2 4 2 increment index value 1 fullword B LOOP go back for next number OVER CLI 0 1 C S was this delimiter BE DONE yes so branch out XPRNT CL30 0 BAD INPUT STOP 30 DONE _ se ee more instructions NUMBERS DS 20F space for 20 values to be stored CARD DS CL80 input workarea SAMPLE USAGE OF XDECO The following converts register 4 to decimal and prints it It assumes a reasonable value in R4 so that the first character o
76. ialize the user program for later execution These include initializing the user RFLAG to the value given by the RFLAG option in the PARM field see PART III Then instead of executing the user program directly the ASSIST Assembler is called to process a test deck which follows the user program 4 During the assembly of the test deck any of the replace program s entry points may be called Any such call is intercepted by the Replace Monitor Using previously saved information it supplies the parameter values to the original ASSIST entry point called which returns the correct set of values to be computed by that entry At this point depending on certain bits in the current value of the user RFLAG various debugging information may be printed This may include the current cardimage being processed the values of 5 parameter registers on entry to the Replace Monitor and their correct values as returned by the original ASSIST module These messages have labels ARO51 ARO52 ARO54 respectively 5 At this point a check is made to assure that the entry point called actually was defined properly by the user If not the AR101 message is given user storage is dumped and the interception of calls is terminated Otherwise the user registers and counters are prepared and the user program executed beginning at the address in his program given by the called entry point The user program is not executed directly but is int
77. ich type of ASSIST is being used see PART IV B l a TD This supplies the time remaining for a user completion dump and should generally be set to a large enough value to permit at least a partial dump to be given thus showing the user the instructions being xecuted especially if a loop is occurring TD 0 is appropriate for debugged programs which can then use all possible time for execution TX This value is the total time in seconds for user program execution and dump together It controls time in the same way that PX controls pages and RX controls output records see P for description of the process of control values computation ASSIST3 11 XREF This option provides a short but informative cross reference listing following the assembly listing Among other things it does distinguish between two types of references A MODIFY reference is any one in which a symbol is used in a machine instruction field denoting an operand to be modified ST 0 X for example All other references are considered FETCH references B gt er L 0 X DC A X The cross reference output shows a symbol its value and statement numbers of referencing statements with MODIFY references flagged as negative statement numbers Conrol of the output is obtained both by the XREF option and by XREF cards inserted in the source program as desired The latter permit explict control of how references ar gathered
78. llowing test program ADDR 000010 000010 000014 000018 00001A 00001E 000022 000024 000028 00002C 00002E 000030 HIGHADDR LOWADDR LOOP INSTRUCTION EQU LA 0 LOWADDR LA 1 HIGHADDR XOPC 18 XOPC 20 LA 10 50 LR 1 3 AR 4 1 BCT 10 LOOP XOPC 19 XOPC 22 EQU COMMENTS HIGH OW COUNTING ASSIST4 9 ADDRESS COUNTING ADDRESS THE CO UNT FACILITY EAR T HE RE LOOP 50 1OOP COUNT AREA VALUE a GARBAGE FO GARBAGI i IMES R COUNTING TURN OF P STAT F THE T 22 instruction above would print out the following COUNTING PISTICS The XOPC statistical report STATS gt BEGIN ADDR 00001E END ADDR 00001E INSTRUCTION COUNT 0001 STATS gt BEGIN ADDR 000022 END ADDR 000028 INSTRUCTION COUNT 0050 STATS gt BEGIN ADDR 00002C END ADDR 00002C INSTRUCTION COUNT 0001 A FEW EXTRA NOTES are expensive i It should be noted when using the XOPC instructions that they best results nstructions with They should be used sparingly and preferably one facility at a time regard to overhead and time for space ASSIST5 1 PART V OUTPUT AND ERROR MESSAGES A ASSEMBLY LISTING 1 ASSEMBLY LISTING FORMAT The assembly listing produced by the ASSIST assembl
79. mitted and U undefined so that the value is U under ASSIST in many cases where it would be something else under IBM assemblers AIF CONDITIONAL BRANCH IBM assemblers normally assign 4096 as the usual limit for number of AIF and AGO branches See ACTR for the way ASSIST handles this The sequence symbol named in the AIF may precede or follow the AIF statement inside macros Outside macros it may only follow the AIF i e only forward branches are allowed If a branch is taken to a previously defined sequence symbol in open code ASSIST produces an an error message and ignores the AIF AGO AGO UNCONDITIONAL BRANCH AGO follows the same restriction as AIF backwards branches are allowed in macros but not in open code ACTR CONDITIONAL ASSEMBLY LOOP COUNT Gl R ASSIST supports the standard ACTR However the default value of the ACTR counter is set differently via the MACTR option supplied by the user This has a default value as given in PART III which is normally smaller than the IBM value 4096 The MACTR value is used for all macro definitions unless explicitly overridden via ACTR statements CONDITIONAL ASSEMBLY ELEMENTS There are no changes except that attributes L S and I are not supported ASSIST1 12 SECTION 10 EXTENDED FEATURES OF THE MACRO LANGUAG Gl T CJ MNOTE REQUEST FO
80. n at the end of the first control section in the program Expressions Use of general xpressions is permitted for most statements Any restrictions are noted under the individual statements ASSIST1 6 SECTION 3 ADDRESSING PROGRAM SECTIONING AND LINKING USING Use Base Register The first expression address in a USING statement must be relocatable CONTROL SECTIONS Multiple control sections are allowed A program must contain at least one control section Control Section Location Assignment Control sections may not be intermixed under ASSIST i e all the statements of one control section must b coded befor another is begun FIRST CONTROL SECTION Under ASSIST the first control section has no properties different from the other sections Li its initial location counter value must be relocatable and it does not normally contain unassigned literal constants unless it is the only control section START Start Assembly The START instruction may be preceded by listing control instructions and comments cards The same label may not be used on a START statement and a later CSECT statement CSECT Identify Control Section No more than one CSECT may use a given symbol as a name and statements from different CSECT s may not be interspersed DSECT Identify Dummy Section No more than one DSECT may use a given
81. n number of pages by removing some carriage control characters from the printed output such as page and multiple line skips E DECK NODECK Coding DECK causes ASSIST to punch an object deck of the user program assuming that the number of errors did not exceed the NERR option that the version of ASSIST in use has a card punch and that none of the following options were specified also NOLOAD NOPUNCH OBJIN or REPL The deck punched is described in PART IV E 1 of this manual Note that this option should not be used for large programs since every byte of storage of the user program is punched 56 bytes per card Gl even if the storage was reserved by DS or ORG commands Note that the deck while resembling standard S 360 object decks cannot really be used for any purpose but to read back into ASSIST later The user is also cautioned to be careful about using DECK with the RELOC option ASSIST3 5 DISKU NODISKU Coding DISKU causes the ASSIST assembler to place the passl output on intermediate disk storage Pass2 then recovers the passl information from disk to use in the production of object code into ASSIST s dynamic work area Assuming ASSIST is generated with the user controlled DISKU NODISKU option it is possible to assemble much larger programs with A a SSIST using the DISKU option DISKU has no effect when coded with OBJIN nd is compatible with any other
82. n source the last value is used subject to rule 2 It is possible that some values cannot be reset once set anywhere 4 DEFAULT values are used only if they are not coded in either the INVOKING PARM or SJOB cards i e they override only LIMIT DEFAULT values This construct allows for both limit and default values for the numerical options SAMPLE USAGE OF OPTIONAL PARAMETERS 1 EXEC ASACG PARM T 3 5 R 200 NERR 10 RELOC CMPRS 2 EXEC ASACG PARM BATCH CPAGE T 5 TX 2 P 20 PX 5 RX 315 SSD SYSIN DD SJOB ASSIS ACCTH PD 1 TD 0 05 CMPRS SS SSX this job crams output onto fewest possible pages SJOB ASSIS ACCT PD 0 TD 0 RD 0 this is a debugged program saves no pages time or records for the dump gets maximum output SJOB ASSIST ACCT OBJIN thst fs o e object deck The abov xamples show a typical single job run and a typical batch of jobs ERIS The fol A under N col be increased from a under FROM colum llowing lists t sources from which he purpose of each ASSIST Can be ge flagged ICS OF PARAMETERS Each to show 1 LIMIT DEFAULT lumn i ASSIST3 3 he available options including the default each can be specified and brief notes on option is described in detail in the next nerated not to allow certain options and whether they can be omitted or not
83. ng Point Constants E and D No scale or exponent modifiers are allowed but exponents are accepted within each constant Decimal Constants P and Z If no explicit length is supplied for an operand containing multiple constants each of the operands is assembled to the length of the last constant in the operand even if truncation is thus required For example under th standard assembler the following needs four bytes Under ASSIST it is assembled into three bytes with the second constant truncated DC P 0 20 1 Address Constants only A and V address constants are allowed Complex Relocatable Expressions are not allowed A type Address Constant may not be used in a literal constant if it refers to the location counter It will be assembled improperly if it does so Y Type S Type and Q Type Address Constants are not allowed ASSIST1 8 CCW DEFINE CHANNEL COMMAND WORD The CCW is recognized and allocated storage but is not otherwise assembled It will be flagged NOT CURRENTLY IMPLEMENTED Listing Control Instructions TITLE IDENTIFY ASSEMBLY OUTPUT No title may have a symbol in the name field PRINT PRINT OPTIONAL DATA All operands are accepted but DATA and NODATA have no effect i e no more than eight bytes of data are ever printed Any statement flagged with an error or warning is always printed even if the print control is OFF or NOGEN f
84. ng more is done 3 From one to nine decimal digits are scanned and the number converted to binary and placed in REG with the appropriate sign The condition code is set to 0 0 1 or 2 depending on the value just placed in REG 4 Register 1 is set to the address of the first non digit after the string of decimal digits Thus REG should not usually be 1 This permits the user to scan across a card image for any number of decimal values The values should be separated by blanks since O t therwise the scanner could hang up on a string like 123 unless he user checks for this himself I e XDECI will skip leading blanks but will not itself skip over any other characters 5 During step 3 if ten or more decimal digits are found register 1 is set to the address of the first character found which is not a decimal digit the condition code is set to 3 and REG is left unchanged A plus or minus sign alone causes a similiar action with Rl set to the address of the character following the sign character XDECO XDECO converts the value from REG to printable decimal with leading zeroes removed and a minus sign prefixed if needed The resulting character string is placed right justified in a 12 byte field beginning at ADDRESS It can then easily be printed using an XPRNT instruction The XDECO instruction modifies NO registers ASSIST2 5 SAMPLE USAGE OF XDECI T
85. notes the maximum number of errors permitting execution and that the user program will not b xecuted because th NERR limit value has been overrun see PART III regarding NERR E DYNAMIC CORE AREA USED LOW HIGH LEAVING 4 FREE BYTES AVERAGE Hitt BYTES STMT The ASSIST assembler uses memory from the opposite ends of one area of storage acquired at execution time The LOW area contains source statements and generated object code the HIGH area contains the symbol and literal tables and the space remaining indicates how close the user is to causing a storage overflow The average cor usage printed includes that used in both LOW and HIGH areas al ASSEMBLY TIME SECS STATEMENTS SEC This notes the total time used by the assembler along with the rate of assembly At PSU this time includes both CPU time and I O charges e X X EXECUTION DELETED LESS THAN PER CENT OF MACHINE INSTRUCTIONS HAVE COMMENTS The above message may appear before the core area message if the ASSIST has the comment checking option and either COMNT was coded or was invoked by account number and the user did not put comments on the given percentage of machine instruction statements ASSISTO 11 B ASSIST MONITOR MESSAGES 1 HEADINGS AND STATISTICAL MESSAGES The main control program of ASSIST may issue the following headings and messages during execution
86. ogram will be assembled When the program is xecuted fetch protection is eliminated which the execution time relocation value of zero allows the user program to examine any areas of storage in the computer for example to trace system control blocks RELOC mode is implied if REPL is coded REPL NOREPL REPL notes that the user supplies two source programs of which the first is a replacement for one of the modules of the ASSIST assembler and the second is a test program to be assembled using the replacement program This optional feature is described in detail in the ASSIST ASSEMBLER REPLACEMENT USER S GUIDE RF LAG This option specifies an initial value for the replace control flag it is meaningful only if REPL is coded and is described in the ASSIST ASSEMBLER REPLACEMENT USER S GUIDE za ASSIST3 9 RX This gives the total number of output records for user program execution and dump together s R It corresponds to PX for page control and is used in the same way SS NOSS This option is effective only if CPAGE is on and is useful for reducing the number of pages printed for a given number of lines output Using SS essentially converts all carriage controls to single space commands except for page skips which become double spaces and no spaces which are unchanged SS is effective during the assembly phas
87. on is brought about by its similarity in format to the s360 s370 Supervisor Call Instruction SVC The XOPC instruction is of the RR type Its general format is as follows The number residing in the second byte of the instruction controls which specific XOPC instruction will be executed Up to 256 0 255 different instructions can be executed using XOPC However at present only 23 XOPC instructions are implemented There is very little error checking involved with the inter pretation of the XOPC instruction The condition code is used to tell the user programmer about XOPC instruction errors and is set during execution of the instruction as follows cc 0 Instruction is valid CC 1 Illegal or Incorrect Argument s used CC 3 Specified code number is not implemented When a specified XOPC instruction is found to be in error the condition code is set as described above and the instruction execution is ignored No other error checking is provided It should be noted that XOPC instruction errors cannot cause execution time interrupts ABENDS Below is a description of the 23 XOPC instructions presently implemented ASSIST4 3 XOPC 0 SET PSEUDO SPII J EXIT ADDRESS This instruction allows the user to set a type of SPIE Th user specifies an address and the interrupts he wishes to process in a coded form When this instruction is xecuted Register
88. opened A SYSLIB DD card is missing or in error GENERATED STMTS OVERWRITTEN During macro expansion one or more generated statments were lost due to internal table management probably because a statement near the beginning of a macro generated a long literal constant One solution is to insert several comments cards at the beginning of the macro definition DYNAMIC STORAGE EXCEEDED ASSIST requires more storage than is available so the assembly is halted This can occur for many reasons REMEDIES use the DISKU option if available remove comments cards from your program cut down on array sizes etc ASSIST5 10 4 ASSEMBLER STATISTICS SUMMARY Following the assembly listing the assembler prints three or four lines of statistical information as follows a xxx STATEMENTS FLAGGED WARNINGS ERRORS This notes the total numbers of statements flagged warning messages and error messages given during the assembly b xxx x x NUMBER OF ERRORS EXCEEDS LIMIT OF ERRORS PROGRAM EXECUTION DELETED This
89. or generated statements PROGRAM CONTROL INSTRUCTIONS ICTL INPUT FORMAT CONTROL ISEQ INPUT SEQUENCE CHECKING PUNCH PUNCH A CARD and REPRO REPRODUCE FOLLOWING CARD are not accepted by ASSIST LTORG BEGIN LITERAL POOL Any literals used after the last LTORG are placed after the END card instead of at the end of the first control section Duplicate Literals Duplicate literals are never stored since the programmer may not refer to the location counter in a literal A type address constant the only cas under th regular system requiring the storing of duplicate literals COPY COPY PREDEFINED SOURCE CODING is not allowed ASSIST1 9 SECTION 6 INTRODUCTION TO THE MACRO LANGUAG Gl The macro language is a facility which may or may not be included in a particular version of ASSIST Also various levels of the ASSIST macro processor can be generated so that the user should check to see which one s are available at his installation The following facilities may be available BASIC F MACRO FACILITY allows programmer written macros compatible with Assembler F but without macro library or open code conditional assembly EXTENDED G amp H MACRO FACILITY like BASIC above but allows certain features not supported by Assembler F but allowed by Assemblers G or H MACRO LIBRARY some versions of A
90. orrect override of this This message appears in the ASSIST is unable to open the DCB for the source card SYSIN DD card is probably TO6FOO1 This is probably caused by lack of a DD card or DDNAME in a omitted assembly and execution impossible system messag class data set if for its printer using DDNAME by an catalogued procedure ASSIST COULD NOT OPEN READER SYSIN ABORT system message class data set VE reader The or mispunched making an STORAGE The user program assembled memory remaining to set up The user should attempt to his program This message OVERFLOW BEFORE EXECUTION properly control blocks required reduce the amount should occur very seldom EXECUTION DELETED but there is Lor storage insufficient execution used by of NORMAL USER TERMINATION BY RETURN This message is issued if the user program branches to the address originally supplied to it as a return address in register 14 If this message appears no completion dump is printed TIME OR RECORDS HAVE BEEN EXCEEDED This message is printed if the time or record limits have been exceeded at any time during a job This message appears after a completion dump if there is one ASSIST5 13 C ASSIST COMPLETION DUMP When a user program terminates abnormally a completion dump
91. ory quickly CALL SAVE RETURN 11 use IHBERMAC XSAVE and XRETURN contain GETMAIN and FREEMAIN to upport the REEN option and GETMAIN FREEMAIN both call IHBERMAC nother example is using ASSIST to check out a QSAM program ask for PEN CLOSE GET PUT and DCB ASSIST processes these correctly but 700 statements are added to the program by the macros and all of the nner macros A simple program can easily require 250K bytes of memory for assembly given such macros ct HNO YP a w Given the above circumstances care must be taken with the library facility in order to mak fficeient use of it Given such care ASSIST is fast and small enough to check out fairly large programs in a reasonable amount of memory and time The following are useful tricks for saving time and space CJ 7 des WRITE REDUCED VERSIONS OF COMMON MACROS AND PLACE THEM IN A SPECIAL LIBRARY TO BE ACCESSED FIRST BY ASSIST For example remove th REEN option from XSAVE XRETURN replace IHBERMAC calls by MNOTEs in CALL SAVE RETURN etc Qe USE LIBMC OPTION TO EXAMINE LIBRARY MACROS WRITE DUMMY MACROS TO KEEP UNUSED ONES FROM BEING FETCHED For example if you know
92. ource 1234 NO 10 total run page limit if CPAGE on 1234 NO 1 page limit for dump if CPAGE on 1 2 O PUNCH select real punch or print simulated 1234 NO 5 execution dump page limit if CPAGE 1234 N 10000 output record limit linestcards 1234 N 25 records saved for dump 1234 O NORELOC relocate to real address store protec 1234 O NOREPL assembler replacement run 1234 o 0 replace option flag only if REPL on 1234 N 10000 execution dump record limit 1234 O NOSS single space assembly only if CPAGE 1234 O NOSSD single space dump only if CPAGE 1234 O NOSSX single space execution only if CPAGE 1234 NO 100 total run time seconds 1234 NO 1 time in seconds saved for dump 1234 N O 100 time in seconds for execution dump 1234 O 0 3 3 requests cross reference ASSIST3 4 C DESCRIPTION OF INDIVIDUAL OPTIONS This section describes each of the options which may be available under ASSIST Refer to the previous section for default values and other information regarding the usage of these options ALGN NOALGN Use of the NOALGN option allows the user to suppress specification interrupts caused by improper alignment of operands This is useful when using a S 360 computer to simulate a S 370 which may of course use data on any boundaries for many opcodes Not every ASSIST allows this BATCH NOBATCH The BATCH option allows multiple jobs to be run in one invocation of ASSIST It is described in Part III A of this manual CMPRS NO
93. perand appears twice or more in the list of operands AS210 MNEST LIMIT EXCEEDED The MNEST option provides a maximum limit to the nested depth of macro calls This limit has been exceeded Note that after the MSTMG limit has been exceeded the MNEST limit is effectively 0 AS211 ILLEGAL ATTRIBUTE USE ASSIST does not support S I or L for macro operands AS212 GENERATED STATEMENT TOO LONG A STATEMENT WAS GENERATED HAVING MORE THAN TWO CONTINUATION CARDS AS217 STMT NOT PROCESSED PREVIOUS ERROR STMT MACRO nam During expansion of macro name the statement numbered was encountered but not expanded because it had already been flagged J AS218 STORAGE EXCEEDED BY FOLLOWING MACRO EXPANSION The following call to the macro listed caused overflow of storage probably due to looping Use ACTR MACTR or MSTMG AS220 UNDEFINED SEQUENCE SYMBOL IN STATEMENT This may appear following an entire macro definition and gives the number of a statement referencing a sequence symbol never defined Any of the following messages describes an ASSIST5 8 expansion of statement of macro name a descriptive value such as an offending sub messages below use as an
94. resses are specified ASSIST will use the high outer limits for the limit addresses Storage Modification Checking line pri storage Assume the instruction liste ADDR INSTRUCTION 0001C0 ST R1 SAVE Here is the line printed assuming the 0002C0 CHECK gt INSTR ADDR 0001C0 INSTR MODIFICATION LIMIT ADDRS gt LOW 000 XOPC 7 SET ADDRESSES as STORAGE MODIFICATION This instruction combines the XOPC 6 instructions above T XOPC 8 TURN OFF STORAGE This instruction disables the Checking Facility XOPC 9 TURN ON BOUNDAR This instruction turns on bou ASSIST4 5 MODIFICATION CHECKING FACILITY Storage Modification Checking is instruction the user should However if no limit addresses est and lowest program addresses Below is an example of the nted when an instruction modifies d below is executed label SAVE has a displacement of z SOLO EZCO 2C0 HIGH 0002C3 in XOPC 5 and TURN ON THE CHECKING FACILITY actions of the XOPC 5 and MODIFICATION CHECKING FACILITY Storage Modification Y ALIGNMENT CHECKING FACILITY ndary alignment checking in ASSIST This implies that SOC6 alignment interrupts will be allowed The default condition within ASSIST occur Thus this instruction need b allows Alignment Interrupts to of an XOPC 10 instruction has sh Alignment Checking Facility see XOPC xecuted only after execution ut off
95. rminates with the standard ASSIST instruction limit exceeded error printed XOPC 16 TURN ON THE INSTRUCTION EXECUTION COUNT FACILITY This instruction enables the INSTRUCTION EXECUTION COUNT FACILITY This facility counts each instruction xecuted between two limit addresses It should be realized that upon its initial execution this instruction will cause ASSIST to allocate a section of main memory equal in size to that of the user program If this space is found to be unavailable the condition code of the user program is set to one and the count facility remains disabled Prior to the execution of this instruction the user should have specified two limit addresses for the count facility See XOPC 17 below However if two limit addresses were not specified ASSIST will use the highest and lowest program addresses for the limit addresses Note This instruction does not clear the instruction counting area See XOPC 20 for clearing the count area E XOPC 17 SET ADDRESSES FOR THE INSTRUCTION COUNT FACILITY IECF XECUTION This instruction specifies boundary limit addresses used by IECF Once enabled this facility will count the number of executions of each instruction between the two limit addresses specified by this instruction When this instruction is xecuted th low and high IECF limit addresses are assumed to be in registers 0 and 1 respectiv
96. rsion of various constant types and evaluation of defining terms and general xpressions Th process can be performed with low overhead HETT PLGD 01 A 1973 ogrammer who allows the tain program odules which allowing for ant segments modules for scanning and both self in core while allowing the user program no possible way to damage the ASSIST system The first part of this manual briefly describes structure of the ASSIST assembler and lists the replacement process Also included ar th replacement and batched the rest of th internal steps in overall linkage conventions required of all replacable modules available to the writer of a replacement module he third section shows the deck setup he second section describes the additional debuggin Job Contr and PARM options needed to make a replacement run he fourth section lists all messages which may be the ASSIST Replace Monitor during a replacement run ASSIST The reader should be familiar with the follow INTRODUCTORY ASSEMBLER USER S MANUAL The above manual gives various information which may be write a program which can be run under ASSIST and explains the various messages which may generated other than Repl Note also that this manual is structured simil For replacement of certain of the modules examine the following manual for additional AS
97. s O and 1 are assumed to contain certain arguments Register 1 must contain a user program address Exit Address to which control is passed if any of the specified program interrupts occur The last 15 bits bits 17 31 of Register 0 must contain a code specifying which interrupts the user wishes to intercept The first 17 bits of register O are ignored Each of the bit positions 17 to 31 of register 0 correspond to one of the 15 execution time interrupts A 1 in one of the bit positions specifies a spie exit on the corresponding program interrupt For example Bit 17 1 specifies a spie exit on socl Bit 18 1 specifies a spie exit on SOC2 Bit 31 1 specifies a spie exit on SOCF A zero in any of the bit positions allows the corresponding execution time interrupt to occur as if no spie had been set Example If register 0 contains the following 0000 0000 0000 0000 0111 0000 0000 0001 After an XOPC 0 instruction has been executed with register 0 as above control will be passed to the address found in register 1 if any of the following interrupts occur S0C1 S0C2 SOC3 and SOCF If a spie exit address has been given i e This instruction has been executed and one of the specified interrupts occurs the following actions take place 1 The current values of user register 0 and 1 are saved 2 The PSW at interrupt is loaded into registers 0 and 1 3 The proper interrupt code is inser
98. s but are more commonly used as work temporary work registers RAT EQU R12 ASSEMBLER TABLE POINTER READ ONLY This register points the main assembler table VWXTABL csect AVWXTABL dsect during an assembly No subroutine in the assembler may modify this register RSA EQU R13 SAVE AREA POINTER BASE REG FOR SOME This register is used to point to an OS 360 save area for any subroutine which may call another Almost all subroutines use this as a base register if they are not lowest level routines RET EQU R14 RETURN ADDRESS USED IN CALLS This is used in subroutine linkage for the return address to a calling program This symbol is generally used whenever subroutine linkage is being set up while R14 is used when the register is being used as a temporary work register REP EQU R15 ENTRY POINT ADDRESS OFTEN USED BASE This register is used to hold the entry point address for all subroutines in the assembler Lowest level routines usually use this as a base register In other routines this may be used as a local work register in which case the symbol R15 is normally coded ASREPLGD 07 2 LINKAGE CONVENTIONS THE ASSEMBLER The linkage conventions inside the ASSIST assembler consist of a few modifications to the standard OS 360 linkage conventions which have been changed mainly to save time and space The differences are as follows a Registers RO R6 or RO R2 RW RZ are prot
99. s extra program statistics extra abnormal termination completion information a facility allowing the programmer to change machine emulation during execution an instruction trace facility an instruction counting facility and a 1 t arger subset of S360 S370 instructions The ASSIST interface with h interpreter Econtrol Block has been extended but upwards ompatibility with the entire assist system is maintained The ASSIST Optional Extended Interpreter is somewhat larger and executes slightly slower than the original Assist interpreter This is caused by the extensively table driven nature of the extended nterpreter and the addition of all of the new features p ASSIST4 2 B THE XOPC OPTIONS CALL DEBUGGING AND ANALYSIS INSTRUCTION The OPtions Call pseudo instruction can provide the user programmer with several functions 1 Set a type of SPIE in ASSIST giving the user the capability to process specified execution time interrupts 2 Trace instructions as they ar xecuted 3 Check which areas of storage are being modified by which instructions 4 Purposely cause an execution time interrupt when a certain number of instructions hav been xecuted 5 Control Boundary Alignment Checking Turn off and on the allowance of SOC6 alignment interrupts and 6 Count and print statistics of the number of instructions xecuted between two specified addresses The flexibility of this instructi
100. s called by use of the OBJIN parameter and loads object deck cards having the format given on the previous page ignoring all cards having neither TXT nor END in columns 2 4 The usual use for this option is to load a deck previously produced by ASSIST or possibly by some student written compiler being tested However it is possible to link decks produced by the standard system assemblers if the guidelines below are followed a Use no V type adcons b Any command listed in PART II of this manual XREAD XDUMP etc is handled inside ASSIST as a special instruction using one or more of the opcodes not already used If any of these commands is to be used equivalent code must be generated c If multiple assemblies are used th only way to communicate among them is to assemble each at some fixed location known to any of the others which reference it in any way Regardless of the method used to create the input deck the entire object deck must follow the rules below a The address on the first TXT card must be less than or equal to all other TXT card addresses received The object code for this address is placed starting at the first byte of available memory b The difference between the highest address of received object code and the lowest address cannot exceed the available storage c The entry point address is either the address from the first END card specifying one i e not blank or if no such address is
101. s taken from register 0 if the halfword is all zero EXAMPLES XREAD 0 1 2 100 gt X E00120000064 XPRNT 2 3 4 1 gt X E02340021000 COMMAND OPCODE MASK LENGTH OPERAND FORMAT XDECI x53 4 bytes normal RX XDECO EA z 4 bytes normal RX XDUMP X El 6 bytes register form no operands last five bytes totally ignored XDUMP X EO 6 6 bytes storage form RX SS XGET X EO A 6 BYTES RX SS XHEXI x 61 4 bytes normal RX XHEXO X 62 4 bytes normal RX XLIMD X EO0 8 6 bytes RX SS XPNCH X EO 4 6 bytes RX SS XPRNT X EO 2 6 bytes RX SS XPUT X EO C 6 bytes RX SS XREAD X EO 0 6 bytes RX SS XREPL X AO o 4 bytes sI immediate field gives operation INPUT OUTPUT INSTRUCTIONS XREAD XPRNT XPNCH Basic input output facilities are provided by XREAD card READer XPRNT line PRiNTer and XPNCH card PuNCH They are written using the following format label XMACRO area length label is an optional statement label XMACRO is XREAD XPRNT XPNCH area is the address in memory to be read or written This area may be specified by an RX type address i e anything legal as the second operand of a LA instruction such as 0 1 2 AREA2 10 CARD 1 3 or CL30 0 MESSAGE length specifies the number of bytes to be read or written This length can range from 1 to the maximum length for the appropriate device 80 for XREAD XPNCH 133 for XPRNT The length field may be omitted in which case the maxim
102. s that for the instructions XREAD XPRNT XPNCH Thus the length may be given as a register number enclosed in parentheses or may be omitted in which case a length of 1 is assumed If the combined area address plus the length yields an address greater than the highest user address or if the length is 1 the highest user address is used as an upper limit instead Thus storage will be printed to the end of the user program The suggested method of using XLIMD is to place all variables at the end of the program then execute an XLIMD with an area address specifying the first variable desired and omitting the length This will cause the storage to be printed starting at the specfied address and going to the end of the program SAMPLE USAGE OF XLIMD The following program gives a typical way of using XLIMD DUMPTEST CSECT USING 15 XLIMD VARIABL1 set dump limit right away VARIABL1 DS D first variable area XLIMD may be executed any number of times during a program but it is suggested that it be called early in any large program if there is any possiblity that record limits could be exceeded ASSIST2 9 OPTIONAL INPUT OUTPUT INSTRUCTIONS XGET AND XPUT These instructions are similar to XREAD XPRNT XPNCH but are more general allowing the user to specify any filename to be read or written WARNING not all versions of ASSIST support these instructions Also a particular version may only support
103. s the number of pages which should be reserved for the user completion dump phase It is effective only if CPAGE is on and is used in conjunction with P and PX see explanation under P Typical values are as follows PD 0 saves no pages for dump Good for debugged programs PD 1 even if the program loops printing this allows enough information to determine what the program was doing If SSD is coded about 1K of storage can also be seen Note that the PD value does not restrict a dump to that size so that the user also gets up to the PX value for execution plus dump together even if the entire amount is used to provide the dump PUNCH NOPUNCH Use of the NOPUNCH parameter causes the system to print any output from XPNCH instructions rather than punching them Each cardimage is preceded with the characters CARD gt to distinguish it from other printed output This option is useful for testing punching programs Versions of ASSIST with no punch treat all attempted punching this way ASSIST3 8 PX This gives the maximum number of pages for both user program execution and completion dump phases together It is effective only if CPAGE is on See description under P R This value specifies the maximum number of output records lines printed cards punched allowed for the entire run Record counting is always performed and the entire process resembles that of page counting see P and occurs in parallel
104. sses However if no limit addresses have been specified ASSIST will use the highest and lowest program addresses for the limits Below is an example of the trace line printed for each instruction executed Assume this instruction is executed causing the following trace message to be printed ADDR INSTRUCTION OOEBEO ST RO R10 SAVEAREA Here is the trace message printed TRACE gt INSTR ADDR OOEBEO INSTR 980A 6020 XOPC 3 SET ADDRESSES as in XOPC 1 and TURN ON THE INSTRUCTION TRACE FACILITY This instruction combines the actions of XOPC instructions 1 and 2 It assumes register usage the same as in XOPC 1 XOPC 4 TURN OFF THE INSTRUCTION TRACE FACILITY This instruction disables the Instruction Trace MODIFICATION CHECKING XOPC 5 SET ADDR FACILITY ES FOR THE STORAGE ESS This instructio inside which the Storage Modification Checking Facility facility Once enabled this addresses to be monitored length of storage modified and the will be printed for the user n specifies address bou ndaries high and low will operate betw causes storag If any of this instruction The register storage usage n is modifying upon th boundary modified the the storage execution of this instruction is the same as in XOPC 1 above XOPC 6 TURN ON THE STORAGE T This instruction enables the Facility Before th xecution of th have specified two boundary add
105. ted into user register O bits 17 thru 31 of the PSW 4 ASSIST now considers the user in the interrupt processing state 5 Control in the user program is passed to the given interrupt exit address It should be noted that when the user is in the Interrupt Processing State any further interrupt will cause abnormal termination of the user program The user will remain in this state until the exec ution of an XOPC 21 instruction XOPC 0 can be executed an unlimited number of times during the execution of a program to change the specified exit address or to change the interrupts to be intercepted Note however that the most recent execution of XOPC 0 is the one in effect and cancels all previous executions ASSIST4 4 Em E XOPC S FOR TH FACILITY INSTRUCTION TRACE ET ADDRESS ES This instruction specifies boundary addresses used by the trace facility Onc nabled the trace facility will give the user a printed trace of all instructions executed within these two boundary addresses When this instruction is executed the lower and upper trace address limits are assumed to be in registers 0 and 1 respectively XOPC 2 TURN ON THE INSTRUCTION TRACE FACILITY This instruction enables the trace facility Prior to the execution of this instruction the user should have specified two limit addre
106. that a given macro will NOT actually be called write a dummy like ACRO IHBERMAC amp A amp B amp D amp E amp F amp H NOTE 4 PSEUDO IHBERMAC CALLED amp A amp B amp D amp E amp F amp H END 3 IF NECESSARY USE THE DISKU OPTION IF AVAILABLE Th intermediat text saved between the two passes can be spilled to disk drum thus allowing more space for macro dictionaries symbol table etc ASSIST2 1 PART 11 INPUT OUTPUT AND DEBUGGING INSTRUCTIONS ASSIST accepts as special machine instructions some commands which are handled by 0S 360 as macro instructions They essentially permit the user to read and punch cards print lines and dump the contents of his registers and storage areas They also provide easy input output conversions for decimal numbers The following table gives th ncodings of the special commands of ASSIST which use currently undefined opcodes and ARE SUBJECT TO CHANGE AT ANY TIME In some cases a Mask field is used to differentiate among different commands using the same opcode The notation RX SS under the columns for OPERAND FORMAT implies that the first four bytes of the instruction follow standard RX format with the Mask field giving the specific type of operation The third halfword specifies th length which is encoded in the same way as are lengths in Shift instructions xcept the length i
107. tions it performs These options are of two types the first kind show yes no values and are coded as a specific name with or without a preceding NO Every option has a default value and some of the numerical ones have upper limits which can never b xceeded Each parameter can possibly be given values from at most four different sources which are as follows 1 LIMIT DEFAULT absolute upper limits on some numerical options and default values for some others defined inside ASSIST 2 INVOKING PARM values for any of the options EXEC CARD PARM field or PARM supplied by another program calling ASSIST NOTE this is not available under DOS 360 3 JOB CARD PARM values for some of the options if desired only possible if LIMIT DEFAULT or INVOKING PARM specified BATCH DEFAULT default values for the numerical parameters having upper limits only used if values not specified in 2 or 3 defined inside ASSIST 4 For any assembly execution dump cycle of ASSIST i e one program the above sources of information are processed in the order given above subject to the following rules 1 Some options can be supplied values only from certain sources 2 Certain numerical parameters can never be increased beyond any previous setting from any source This particularly applies to time records and pages limits 3 In most cases if the same option is coded several times in the same informatio
108. um length is used by default It may also be specified as a register nclosed in paren theses indicating that the length will be supplied at execution time from the designated register ASSIST2 2 CONDITION COD Ed XPRNT and XPNCH do not change the condition code XREAD sets the condition code to indicate normal processing or end of file as follows CC 0 a card was read and length characters placed in user s area CE 1 nd of fil ncountered no more cards can be read found CARRIAGE CONTROL XPRNT requires that the first character of the area be a valid carriage control character such as blank single space 07 double space and 1 new page or any others which are available EXAMPLES OF XREAD XPRNT XPNCH USAGE The following section of a program reads in a deck of cards until an end of file card is found punches the last 70 characters of each card into the first 70 columns of each card punched and prints some number of characters from each card where the number 1 had been previously loaded into register 5 the 1 is for the carriage control character The cards are double spaced on the printer READLOOP XREAD CARD read card using omitted length BNZ NOMORE if CC 1 branch out BC 4 NOMORE or BM NOMORE would also work XPNCH CARD 10 70 punch 70 bytes explicit length XPRNT CARD 1 5 print number of bytes using carria
109. vel Assembler features added if available MACRO H H level Assembler features added if available If macros or conditional assembly are to be used the user MUST specify something other than MACRO N See also APPENDIX K of PART I MACTR This provides a default value for the starting ACTR counters in all macros used It can be overridden by explicit ACTR statements MNEST This gives a limit on the maximum level of nested macro calls thus allowing prevention of unwanted recursion in macros MS TMG This provides a global limit on the total statements processed in all macro expansions It is like ACTR but counts all statements in all macros rather than being local to a macro It can be used to prevent macro looping which causes storage to b xceeded NERR This option is used to allow a program to execute even though there are errors in it If omitted the value is assumed to be zero i e the program is not executed if there are any errors at all in it If NERR 10 is used the program runs if it has 10 errors but does not run if there are 11 Note that warning messages are not included in this count only actual error messages OBJIN NOOBJIN Coding OBJIN informs ASSIST that an object deck is being supplied to it in place of the usual assembler source deck This is allowed in every case unless REPL is coded in which case OBJIN is ignored The format required of the object
110. xpected to make sense MACRO PRGMAC1 amp ARG CALL X MEND SYSLIB SAVE WE WILL NEED SAVE MACRO SYSLIB RETURN EQUREGS OTHER MACROS NEEDED CALL USED IN PRGMAC1 IS NOT NEEDED BUT COULD BE ABOVE USING 15 SAVE 14 12 PRGMAC1 RETURN 14 12 EQUREGS ASSIST1 14 HINTS ON OPTIMAL USE OF MACRO LIBRARY T The user should be aware of the following when using the macro library facility I The macro processor is mainly intended to process programmer written macros Among other things all macro dictionaries and tables are kept in memory for the sake of speed 2 Most IBM macros and many XMACROS call inner macros which call other inner macros which call others Ec Eds Thus calling one macro from the library may cause many others to be brought in In particular almost every IBM macro calls the macro IHBERMAC to issue MNOTE statements for any error messages IHBERMAC contains over 400 statements with many memory consuming MNOTEs included 3 If a macro is referenced it is fetched from the library whether it is actually ever called or not For example IHBERMAC is only called when there is an error but is always fetched 4 Given the combination of 1 2 3 above lt is easily possible to use macros like CALL SAVE RETURN XSAVE XRETURN which do not in themselves seem large but exceed mem

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