controller user's manual
Contents
1. RKi1 D and RK11 E moving head disk drive controller user s manual dlileli tal EK RK11D OP 001 RK11 D and RK11 E moving head disk drive controller user s manual digital equipment corporation maynard massachusetts Ist Edition September 1976 Copyright 1976 by Digital Equipment Corporation The material in this manual is for informational purposes and is subject to change without notice Digital Equipment Corporation assumes no respon sibility for any errors which may appear in this manual Printed in U S A The following are trademarks of Digital Equipment Corporation Maynard Massachusetts DEC DECtape PDP DECCOMM DECUS RSTS DECsystem 10 DIGITAL TYPESET 8 DECSYSTEM 20 MASSBUS TYPESET 11 UNIBUS CHAPTER 1 1 1 1 2 1 3 1 3 1 1 3 2 1 3 2 1 1 3 2 2 1 3 2 3 1 3 2 4 1 3 2 5 1 3 2 6 1 3 2 7 1 3 2 8 1 3 2 9 1 4 1 5 1 6 CHAPTER 2 2 1 2 2 2 3 2 4 2 5 2 6 CHAPTER 3 31 3 2 3 3 3 4 3 5 3 6 Figure No CONTENTS Page GENERAL DESCRIPTION INTRODUCTION sa atm as 22 nr 2 oe ow ra ar ea ic 1 1 OBTIONS Far a Bees war Sa BAS re en ee dp a 1 1 FUNCTIONAL DESCRIPTION 2 Connor 1 1 Disk Drives 2 2 sie A kek ee ee ef hb UE 1 2 RKI Controler sa Dia asta ara Renate Be 1 2 Control Reset exi 80 00 Ken a A A 1 3 Seek Function sy aas i ut Sana a AT A E a de a ee 1 3 Drive Reset FUNCHON t o SMe Revie CU ea Caen Se eae eR E A 1 3 Write Lock Function ae Soe2. 04 Sector Counter Indicates that the disk heads are positioned over the disk address Equals Sector currently held in the sector address Address SC SA 05 Write Protect Sets when the selected disk is in the write protected mode Status WPS 3 1 Bit 06 07 08 09 11 13 15 Designation Read Write Seek Ready R W S RDY Drive Ready DRY Sector Counter OK SOK Seek Incomplete SIN Drive Unsafe DRU RKOS Disk on Line RKOS Drive Power Low DPL Identification of Drive ID Description and Operation Indicates that the selected drive head mechanism is not in motion and that the drive is ready to accept a new function Indicates that the selected disk drive complies with the following conditions a The drive is properly supplied with power b The drive is loaded with a disk cartridge c The disk drive door is closed d The LOAD RUN switch is set to RUN e The disk is rotating at a proper speed f The heads are properly loaded g The disk is not in a DRU bit 10 of RKDS condition Indicates that the Sector Counter operating on the selected drive is not in the process of changing and is ready for examination If this bit is not set the Sector Counter is not ready for examination and a second attempt should be made Indicates that due to some unusual condition a Seek function cannot be completed Can be accompanied by RKER 15 Drive Error Cleared by a Drive Reset
3. Drive Power Low and the function is aborted If at the beginning of the next sector a loss of dc power is sensed the same error condition is generated That condition DRE and DPL is also set if a dc power loss occurs while the controller is actively transferring data to or froma disk drive CUT OUT ON DOTTED LINE RKI1 D and RKII E Reader s Comments MOVING HEAD DISK DRIVE CONTROL USER S MANUAL EK RK11D OP 001 Your comments and suggestions will help us in our continuous effort to improve the quality and usefulness of our publications What is your general reaction to this manual In your judgment is it complete accurate well organized well written etc Is it easy to use What features are most useful What faults do you find with the manual Does this manual satisfy the need you think it was intended to satisfy Does it satisfy your needs ___________________ Why Would you please indicate any factual errors you have found Please describe your position Name Organization Street Department City State Zip or Country FIRST CLASS PERMIT NO 33 MAYNARD MASS BUSINESS REPLY MAIL NO POSTAGE STAMP NECESSARY IF MAILED IN THE UNITED STATES Postage will be paid by Digital Equipment Corporation Technical Documentation Department 146 Main Street Maynard Massachusetts 01754 Printed in U S A
4. READY which it sets and RKDS 01 through 11 which are not affected Disk drive operation is only affected indirectly as a result of RK11 logic being cleared Control Reset serves as an effective abort because it terminates all controller action however care should be taken during a Write operation as the abort does not occur until completion of the current sector If a Control Reset function is used to abort a function in process to allow a high priority user access to a disk drive that drive must first be checked for head motion indicated by RKDS 06 Read Write Seek Ready If the function is initiated before the heads have stopped a hard error results after which a Drive Reset function must be performed on that drive before it can be used again 1 3 2 2 Seek Function For a Seek function the RK11 directs the selected disk drive to move its head mechanism to the cylinder address specified by RKDA 05 through 12 When this portion of a Seek has been initiated the controller returns to the Ready state RKCS 07 But if the specified cylinder address is greater than 312g the function is aborted and bit 06 nonexistent Cylinder of the RKER is set RKCS 06 Interrupt Done Enable then determines the program reaction The selected disk drive completes the Seek function by moving its head mechanism to the desired cylinder whereupon RKDS 06 R W S RDY is set The time required to initiate a Seek function is normally 1 us but may
5. at the top of the first cabinet supplies ac power for disk drives A through D Power for disk drives E through J is supplied in a similar manner in the second cabinet Drives A through D make up a daisy chained bus of four disk drives connected directly to the controller Drives E through J make up a second daisy chained bus of four disk drives connected directly to disk drive D in the first cabinet The M7700 card of each disk drive contains a rotary switch that defines the physical disk drive bus DR BUS position The first disk drive on the DR BUS is switched to position 1 and is designated disk drive A and so on through disk drive J This configuration may be varied as DR BUS length allows The maximum length of DR BUS is 50 ft The disk drives on the DR BUS terminate in an M930 Terminator module connected to the last drive on the bus For more disk drive system and disk drive information refer to the RK05 Disk Drive Maintenance Manual DEC 00 RK05 DA Both the RK11 D and the RK11 E require an M7700 Rev J or later The RK11 E also requires a G180 Rev K or later but the RK11 D is capable of operating with any revision of the G180 1 5 SPECIFICATIONS Table 1 2 specifies the RK11 parameters in the areas of environmental limits logic format timing format and power requirements and sets forth model designations 1 6 RELATED DOCUMENTS Table 1 3 lists software and hardware documents that pertain to the RK11 Controller Table 1 2 Specifica
6. beginning of each sector and an index pulse indicates the last sector signifying that the sector following is Sector O The DR BUS consists of eight disk drives connected in daisy chain fashion each of which can be write protected either by an RK11 Controller Write Lock function or by manual intervention On a disk cartridge the upper surface is defined as surface O and is active when RKDA 04 SUR is clear If a data transfer requires an overflow from surface 0 SUR is set automatically and surface 1 the lower surface of the cartridge is activated at sector O If a data transfer requires an overflow from surface 1 the RK11 automatically moves the disk drive heads to the next cylinder checks the header word to verify head positioning and resumes the data transfer at sector O of surface O again but this time on a new cylinder Attempting this cross cylinder operation from surface 1 of the last cylinder will result in an error condition RKER 14 OVR For more detailed information on the disk drive operation and the related power supply refer to the RKOS Disk Drive Maintenance Manual DEC 00 HRK05 C D which is shipped with the disk drives That manual also contains a complete description of the DR BUS lines 1 3 2 RK11 Controller The RK11 is divided into four major functional units as shown in Figure 1 2 The Status Control initiates the programmable RK11 functions and monitors logic status conditions The Disk Control monitors disk
7. data words onto the Unibus If the cylinder address is initially incorrect the controller makes 16 attempts jumper selectable to one as previously noted to establish the correct cylinder address before the function is aborted setting RKER 12 As the data words of a sector pass through the controller a one word checksum word is calculated and compared with the checksum read from the disk drive If there is a discrepancy between the two checksums RKER 01 Checksum Error is set and the controller reaction is determined by RKCS 06 IDE and RKCS 08 SSE Stop on Soft Error An RKWC overflow at any time from the start of the Read function stops the NPR data transfers and sets RKCS 07 RDY at the end of the current sector If the RKWC has not overflowed at the end of a given sector the function is continued at the next contiguous sector 1 3 2 7 Write Check Function The Write Check function is used to compare the contents of memory to the contents of a continuous block of data on a disk cartridge The controller first performs a Seek function just as for a Write function and then reads and checks the next header word If the cylinder address is correct the controller waits for SC SA then begins reading the rest of the sector Data and Checksum while performing BUS NPR transfers for each data word Each data word from the disk drive is compared bit by bit with memory data from the Unibus The disk drive checksum in turn is compared with th
8. drive status conditions and controls all disk drive functions The Data Paths transfer parallel data to and from the Unibus and serial data to and from the disk drives The Bus Control interfaces the RK11 with the Unibus for address selection NPR data transfers and interrupt sequences The RK11 contains seven 16 bit programmable hardware registers addressed from the Unibus that provide the software interface between the RK11 and the Unibus Table 1 1 lists these registers and their addresses Table 1 1 RK11 Registers Name Abbreviation Address RK11 Drive Status Register 777400 RK11 Error Register 777402 RK11 Control Status Register 777404 RK11 Word Count Register 777406 RK11 Bus Address Register Current Memory Address 777410 RK11 Disk Address Register 777412 RK11 Data Buffer Register 777416 Through software control the RK11 can perform four control functions Control Reset Seek Drive Reset and Write Lock and four data transfer functions Write Read Write Check and Read Check The hardware poll feature enables more than one disk drive to perform multiple Seek or Drive Reset functions simultaneously The RK11 also initiates an interrupt sequence on the Unibus in response to any of six interrupt conditions described in Paragraph 3 4 1 3 2 1 Control Reset The Control Reset function initializes all internal registers and flip flops and clears all of the bits of the seven programmable registers except RKCS 07
9. function Indicates that an unusual condition has occurred in the disk drive and it is unable to properly perform any operations Reset by setting the RUN LOAD switch to LOAD If when the switch is returned to RUN the condition recurs an inoperative drive can be assumed and corrective maintenance procedures should be begun Can be accompanied by RKER 15 Drive Error Always set to identify the selected disk drive as RKOS Sets when an attempt is made to initiate a new function or if a function is actively in process when the control senses a loss of power to one of the disk drives Can be accompanied by RKER 15 Drive Error Reset by a BUS INIT or a Control Reset function If an interrupt occurs these bits will contain the binary representation of the logical drive number that caused the interrupt ERROR REGISTER RKER Address 777402 Bit 01 02 04 Designation Write Check Error WCE Checksum Error CSE Unused NOTE This is a read only register Top 15 14 13 12 11 10 9 8 A 6 5 4 3 2 1 0 Description and Operation Indicates that an error was encountered during a Write Check function as a result of a faulty bit comparison between disk data and memory data Clears upon the initiation of a new function This is a soft error condition Sets while performing a Read Check or a Read function as a result of a faulty recalculation of the checksum Cleared upon the initiation of any new function This
10. 3 equals the sector address RKDS 00 through 03 hereafter referred to as SC SA A preamble consisting of 15 words of zeroes is written followed by a sync pulse Then the header word is rewritten automatically followed immediately by the data words for the sector As the data words pass through the controller a one word checksum word is calculated and automatically written after the last sector data word followed by one word of zeroes for the postamble If the cylinder address is incorrect the controller makes 16 attempts to establish the correct cylinder address before the function is aborted setting RKER 12 Seek Error Compatibility with the RK11 C which makes only one attempt may be achieved by cutting a jumper on the Status Control module An RKWC overflow at any time from the start of the Write function stops the NPR data transfers and sets RKCS 07 Ready RDY at the end of the current sector If the RKWC has not overflowed at the end of a given sector the function is continued at the next contiguous sector however if the last sector of the disk cartridge is transferred without RKWC having overflowed then RKER 14 OVR Overrun is set 1 3 2 6 Read Function For a Read function the controller first performs a normal Seek function When that is completed the controller waits for SC SA then reads and checks the header word If the cylinder address is correct the controller continues reading the sector and NPR transfers the
11. ally configured as the RK11 D option but may be configured to the RK11 E option by altering the jumpers Details concerning these optional jumper configurations are available on the cover sheets for circuit schematics of modules M7254 M7255 M7256 and M7257 The jumpered connections are also shown in the module engineering drawings which show the jumper function in the logic The crystal on the M7255 module must also be changed for the RK11 E option The 2 88 MHz crystal should be replaced with a 3 09 MHz crystal see DISK 4 UNIBUS IN CONNECTION SLOTS Ai AND Bi DR BUS CABLE SLOTS A2 AND B2 UNIBUS OUT CABLE SLOTS A4 AND B4 Figure 2 1 nani rem aaa ae RK11 Cable Connections 2 2 2 5 INSTALLATION PROCEDURE The jumpers on the modules should be in the desired configuration before the RK11 is installed After the jumpers for option selection have been configured the seven interrupt vector address jumpers and eight address selection jumpers of the M7257 should be configured to the proper values Those values are typically 220 for the vector address and 777400 through 777416 for the address selection refer to engineering drawing D CS M7257 0 1 There are also seven inhibit strobe jumpers on the M7257 module which when cut inhibit the loading of a particular programmable register When the jumpers have been properly configured the de
12. ally written by hardware following 158 words of zeroes The header area of a sector consists of a single word containing the cylinder address from RKDA 05 12 Before a data transfer function is performed the header word is read and checked against the cylinder address portion of the RKDA to ensure that the disk drive heads are positioned above the proper cylinder The Write function always rewrites the header on the disk using the cylinder address portion of the RKDA The sector format for a raw unformatted cartridge is written under program control in conjunction with RKCS 10 Format FMT Paragraph 3 2 The data area consists of 256 y data words These words like all of the words in each area of the sector are 16 bits long in the RK11 D and 18 bits long in the RK11 E The checksum area ofa sector consists of a single word that is the checksum of all 256 data words This checksum is compared by the controller to the checksum that it calculates itself whenever a Write Check Read or Read Check function is performed within a given sector For a Write function the controller calculates a checksum and writes it on the disk cartridge following the last data word Short portions less than 256 data words of a sector may be read or written as long as this short sector is the last sector of the data transfer When a short sector is written the remainder of the sector is automatically written with zeroes The Write Check function may be perform
13. cs are supplied with the RK11 together with instructions and descriptions regarding their use CHAPTER 3 PROGRAMMING CONSIDERATIONS 3 1 INTRODUCTION This chapter discusses the software interface for the RK11 Controller including device registers and their addresses the interrupt process timing considerations and data format 3 2 DEVICE REGISTERS AND ADDRESSES All RK11 software control is accomplished by seven device registers These registers are assigned memory addresses and can be read or written into except as noted using instructions that refer to the respective register addresses The seven device registers their bit assignments and their memory addresses are listed below Unassigned and write only bits are always read as zeroes Any attempt to manipulate unassigned or read only bits has no effect on the bit The INIT signal refers to the initialization signal issued by the processor DRIVE STATUS REGISTER RKDS Address 777400 NOTE This register is a read only register and contains the selected drive status and current sector address DRIVE IDENT DPL RK05 DRU SIN SOK DRY R W S WPS SC SECTOR COUNTER 2 1 0 RDY SA 3 2 1 0 15 14 13 12 11 10 9 8 7 6 S 4 3 2 A 0 1 Bit Designation Description and Operation 00 03 Sector Counter These 4 bits are the current sector address of the selected drive SC Sector address 00 is defined as the sector following the sector that contains the index pulse
14. disk drives and all necessary cabling The RK11 Controller options RK11 D and RK11 E are jumper selectable on the RK11 modules Paragraph 2 4 For details regarding disk drive installation refer to the RK05 Disk Drive Maintenance Manual DEC 00 HRK05 C D 2 2 POWER REQUIREMENTS Power is supplied to the RK11 Controller by the 5 V power supply for the mounting box in which it is positioned For an RK11 mounted in a BA11 Mounting Box PDP 11 20 power is supplied via a PDP 11 system power cable which plugs into slot A3 of the system unit For PDP 11 35 PDP 11 40 and PDP 11 45 use a special power cable is supplied with the equipment 2 3 CABLING REQUIREMENTS Cabling requirements for the RK11 Controller include the Unibus cable connections and the disk drive cable DR BUS connections Figure 2 1 as well as power cabling in certain systems Both the Unibus and the DR BUS use BC11A cables The Unibus In cable plugs into slots Al and B1 of the system unit and the Unibus Out cable plugs into slots A4 and B4 If the system unit is mounted in a mounting box adjacent to other operating units utilizing the Unibus Unibus In and Out connections between the units are made with an M920 Unibus Connector module If the RK11 is the last unit on the Unibus an M930 Unibus Terminator module is plugged into slots A4 and B4 The DR BUS cable plugs into system unit slots A2 and B2 2 4 RK11 D AND RK11 E OPTION CONFIGURATIONS The RK11 Controller is norm
15. e SCP Read Only Hard Error HE Read Only Error ERR Read Only Description and Operation Indicates that the control is ready to perform a function Set by INIT a hard error condition or by the termination of a function Cleared by GO being set If a soft error is encountered when this bit is set a All control action will stop at the end of the current sector if RKCS 06 IDE is reset or b All control action will stop and a bus request will occur at the end of the current sector if RKCS 06 IDE is set For the RK11 D and RK11 E EXB is unused FMT is under program control and must be used only in conjunction with normal Read and Write functions Used to format a new disk pack or to reformat any sector erased due to control or drive failure Alters the normal Write operation under which the header is rewritten each time the associated sector is rewritten in that the head positioner is not checked for proper positioning before the Write Alters the normal Read operation in that only one word the header word is transferred to memory per sector For example a 3 word Read function in Format mode will transfer header words from three consecutive sectors to three consecutive memory locations for software checking Inhibits the RKBA from incrementing during a normal transfer function This allows data transfers to occur to or from the same memory location throughout the entire transfer operation Indicates t
16. e checksum calculated by the controller If any bit is found to be in error RKER 00 Write Check Error is set Controller reaction is then determined by RKCS 06 IDE and RKCS 08 SSE The Write Check function may be performed on a short sector less than 256 data words as long as the number of words write checked is equal to the number of words previously written into the sector 1 3 2 8 Read Check Function The Read Check function is identical to a normal Read function except that no NPRs occur Only the checksum is calculated and compared with the checksum read from the disk drive This function enables the program to know beforehand if a given block of data is readable and error free Because the Read Check is essentially a parity check it must be performed on a whole sector basis only 14 1 3 2 9 Hardware Poll The controller is capable of permitting any or all disk drives to perform a Seek or Drive Reset function simultaneously The hardware poll feature in the Disk Control identifies the logical disk drive in RKDS 13 15 DRIVE IDENT for any disk drive that has completed a Seek or Drive Reset function This poll causes an interrupt if RKCS 06 IDE is set the controller is in the Ready state RKCS 07 set and the controller is not already attempting to initiate an interrupt from some other function If two or more disk drives complete a Seek or Drive Reset function simultaneously the controller interrupts once for each disk drive a
17. ed on a short sector as long as the number of words write checked is equal to the number of words previously written into the sector Because the Read Check function is essentially a parity check it must be performed on a whole sector basis only 3 4 PROGRAM INTERRUPTS A program interrupt is initiated by an interrupt request which can only occur if RKCS 06 IDE Interrupt Done Enable is set Six hardware conditions can generate an interrupt request to the processor a The occurrence of a hard error condition RKCS 14 HE b The presence of a soft error condition RKER 00 WCE or RKER 01 CSE if RKCS 08 SSE is set 3 9 c Completion of transfer of the designated number of words d The acceptance Address Acknowledge of a Seek or Drive Reset function by the selected disk drive freeing the controller for hardware polling or a new function e The initiation of a Write Lock function on a disk drive indicating that the controller is free to perform a new function f The completion of hardware polling RKCS 13 SCP indicating that the disk drive in the DR SEL bits of the RKDA has completed a Seek or Drive Reset function RKDS 06 R W S RDY The interrupt request of the RK11 Controller can be configured at BR levels 4 5 6 or 7 The RK11 is typically set at level BRS Because of the format structure of the RK11 any interruption of the Write function cannot be tolerated until the end of the current sector as it
18. egister or function bits are loaded with the binary representation of the function to be performed by the control when a GO command is initiated These bits are loaded by the program and cleared by BUS INIT They retain the function until altered by the program or cleared enabling the user to continue from a soft error condition with GO A description of each of the eight functions is given in Paragraph 1 3 2 The binary codings are as follows Bit 2 Bit 1 Bit O Operation 0 0 0 Control Reset 0 0 1 Write 0 1 0 Read 0 1 1 Write Check 1 0 0 Seek 1 0 1 Read Check 1 1 0 Drive Reset 1 1 1 Write Lock Reserved for extended bus addresses used in conjunction with the RKBA This 2 bit counter increments each time the RKBA overflows A bus DATO to these bits overrides any RKBA overflow Loaded by the program and cleared by BUS INIT Use of these bits is intended for systems equipped with a memory larger than 32K words When set causes the control to issue a bus request and interrupt to vector address 220 if a A function has completed activity b A hard error is encountered c A soft error is encountered and bit 08 of the RKCS SSE is set d RKCS 07 RDY is set and GO is not set Bit 07 08 09 12 13 Designation Control Ready RDY Read Only Stop on Soft Error SSE Read Write Extra Bit EXB Format FMT Read Write Inhibit Incrementing the RKBA IBA Read Write Unused Search Complet
19. f Interrupt Done Enable is set In the interval between these two events the selected disk drive is busy moving its heads but the controller is free to perform any RK11 function on any other available disk drive Once a disk drive has begun moving its head mechanism only a Drive Reset function can stop it An attempt to perform any other function on a disk drive whose heads are in motion results in a hard error condition The data transfer Read Write Read Check and Write Check functions all begin with an automatic Seek function This allows the user of a single disk drive system to forget about the Seek function completely and initiate data transfer functions directly The hardware poll logic is initiated only for Seek and Drive Reset functions and not for the Seek portion of data transfer functions 3 6 POWER FAIL If any of the disk drive power supplies senses a loss of either ac or de power no new functions can be initiated If only an ac power loss is sensed and a function is in process the current disk sector is completed If at the beginning of the next sector an ac power loss is still sensed but de power is satisfactory e g momentary line power fluctuations the controller waits for ac power to return before starting operation on the next sector as long as the next sector is in the same cylinder However if the heads must be moved to reach the next sector an error condition is generated RKER 155 Drive Error and RKDS 12
20. hat the previous interrupt was the result of some previous Seek or Drive Reset function Cleared at the initiation of any new function Sets when any of RKER 05 15 are set Stops all control action and processor reaction is dictated by RKCS 06 IDE until cleared along with RKER 05 15 by INIT or a Control Reset function Sets when any bit of the RKER sets Processor reaction is dictated by RKCS 06 and RKCS 08 IDE and SSE Cleared if all bits in the RKER are cleared WORD COUNT REGISTER RKWC Address 777406 15 14 13 2 11 10 9 8 7 6 5 4 3 2 1 0 Bit Designation Description and Operation 00 15 WCOO WC15 The bits in this register contain the 2 s complement of the total Read Write number of words to be affected or transferred by a given function The register increments by one after each word transfer When the register overflows all WC bits go to zero the transfer is complete and RK11 operation is terminated at the end of the present disk sector However only the number of words specified in the RKWC are transferred CURRENT BUS ADDRESS REGISTER RKBA Address 777410 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Bit Designation Description and Operation 00 15 BAOO BA15 The bits in this register contain the bus address to or from which Read Write data will be transferred The register is incremented by two at the end of each transfer If the system has extended memory the RKBA will overflow to the EX MEM bits 04 a
21. is a soft error condition The remaining bits of the RKER are all hard errors and are cleared only by a BUS INIT or a Control Reset function 05 06 07 08 09 Nonexistent Sector NXS Nonexistent Cylinder NXC Nonexistent Disk NXD Timing Error TE Data Late DLT Nonexistent Memory NXM Indicates that an attempt was made to initiate a transfer to a sector larger than 134 Indicates that an attempt was made to initiate a transfer to a cylinder larger than 3123 Indicates that an attempt was made to initiate a function on a nonexistent drive Indicates that a loss of timing pulses for at least 5 us has been detected Sets during a Write or Write Check function when the multibuffer file is empty and the operation is not yet complete Sets during a Read function when the multibuffer file is filled and the operation is not yet complete Sets if memory does not respond with a SSYN within 20 us of the time when the RK11 becomes bus master during an NPR sequence Because of the speed of the RKOS Disk Drive it is possible that NXM will be accompanied by RKER 09 Data Late Bit Designation Description and Operation 11 Programming Indicates that RKCS 10 Format was set while initiating a Error PGE function other than Read or Write 12 Seek Error Sets if the disk head mechanism is not properly positioned while SKE executing a normal Read Write Read Check or Write Check function The contr
22. le at ee en Bt ee 1 4 Write Function lt lt BRE Ae ee 1 4 Read Function aa ine A E 1 4 Write Check Function aaaea 14 Read Check Function 2 eene aa ren 1 4 Hardware Poli asa 4 25 10 20 3 ri 2 en a a ee O AE 1 5 PHYSICAL DESCRIPTION 2 Co none 1 5 SPECIFICATIONS u a ae ra ae ee a 1 5 RELATED DOCUMENTS 2 Komm 1 5 INSTALLATION INTRODUCTION is 402 40 2 3 228 2 2 22 2 38 ana En aaa 2 1 POWER REQUIREMENTS y croson 0 nn 2 1 CABLING REQUIREMENTS aaa 2 1 RK11 D and RK11 E OPTION CONFIGURATIONS 2 22 2020 2 1 INSTALLATION PROCEDURE 2 00 0 0 eee ee ee 2 3 INSTALLATION TESTING 2 ee ee 2 3 PROGRAMMING CONSIDERATIONS INTRODUCTION coro a aa aan ar a 3 1 DEVICE REGISTERS AND ADDRESSES 7 2 1 2 3 1 DATA FORMAT a cus 22 Rn a a a ee 3 9 PROGRAM INTERRUPTS oee saison een 3 9 TIMING CONSIDERATIONS e rA oa n Cm a nen 3 10 POWER PAIL 22 5534 2 SE WS A ra ake ats nr en 3 10 ILLUSTRATIONS Title Page RK11 D and RK11 E Disk Drive System 2 onen a 1 1 RK11 Controller Functional Block Diagram o 1 2 RKEYI Cable C nnections yl aaa Dealer A e EE dt O 2 2 iii Table No 1 1 1 2 1 3 TABLES Title Page RKII Registers u weer LAR AS ee a ED a A aA 1 3 Specifications Sa a A US aR ae rs 1 6 Related Documents s aor a om more nen 1 6 iv INTRODUCTION This manual provides the user with the ins
23. nd 05 of the RKCS to reflect the extended bus addresses DISK ADDRESS REGISTER RKDA Address 777412 CYLINDER ADDRESS SECTOR ADDRESS 5 4 3 3 2 1 0 10 9 8 7 6 gt 4 02 1 0 NOTE This register will not respond to commands while the controller is busy Therefore RKDA bits are loaded from the bus data lines only in the Control Ready RDY bit 07 of the RKCS state and are cleared by BUS INIT and Control Reset The RKDA is incremented automatically at the end of each DRIVE SELECT 2 1 15 14 13 12 11 disk sector Bit Designation 00 03 Sector Address SA 04 Surface SUR 05 12 Cylinder Address CYL ADDR 13 15 Drive Select DR SEL DATA BUFFER REGISTER RKDB Address 777416 15 14 13 12 11 Bit Designation 00 15 DBOO DB15 Read Only Description and Operation Binary representation of the disk sector to be addressed for the next function When active enables the lower disk head so that operation is performed on the lower surface when inactive enables the upper disk head Binary representation of the cylinder address currently being selected The largest valid address or number for the cylinder address is 3123 Binary representation of the logical drive number currently being selected Description and Operation The bits of this register work as a general data handler in that all information transferred between the control and the disk drive must pass through this register Loaded from the b
24. nd identifies each in turn to the RKDS In this situation the processor interrupt status must be raised to a level equal to or greater than that of the RK11 or else a second interrupt will occur immediately after the first causing the interrupt service routine to be interrupted Similarly back to back interrupts will also result from directing the heads to a cylinder at which they are already positioned with the first interrupt coming from the initiation of a Seek function and the second coming from notification from the hardware poll that the heads are already at the desired address In this case also care should be taken in the assigning of processor priorities to handle this situation 1 4 PHYSICAL DESCRIPTION The RK11 Controller consists of the four RK11 modules M7254 M7255 M7256 and M7257 and one system unit The system unit containing the modules can be mounted in any PDP 11 15 11 20 11 35 11 40 or 11 45 mounting box when used in conjunction with the proper power harness The modules utilize many MSI integrated circuits ICs The RK11 Disk Drive System consists of the Controller disk drives and the necessary cabling Disk drives A through D Figure 1 1 are contained in a standard 19 in PDP 11 cabinet which can be configured as part of a system or made to stand alone Disk drives E through J are mounted in a second 19 in cabinet which is always bolted to the left side of the first cabinet An 860 C D Power Control Unit located
25. ol checks 16 times before flagging this error A simple jumper change will force the control to check just once 13 Write Lockout Sets if an attempt is made to write on a disk that is currently Violation WLO write protected 14 Overrun Indicates that during a Read Write Read Check or Write Check OVR function operations on sector 13g surface 1 of cylinder address 3123 were finished and the RKWC has not yet overflowed This is essentially an attempt to overflow out of a disk drive 15 Drive Error Sets if one of the drives in the system senses a loss of either ac or DRE dc power and a function is either initiated or in process while the selected drive is not ready or in some error condition CONTROL STATUS REGISTER RKCS Address 777404 Cerro 15 14 13 12 11 10 9 8 7 6 FUNCTION GO 2 1 5 4 3 2 1 0 X MEM 1 0 Bit Designation Description and Operation 00 GO Loaded by the operator Causes the control to carry out the Write Only function contained in bits Ol through 03 of the RKCS Function Remains set until the control actually begins to respond to GO which may take from 1 us to 3 3 ms depending on the current operation of the selected disk drive to protect the format structure of the sector 34 Bit 01 03 04 05 06 Designation Function Read Write Memory Extension MEX Read Write Interrupt on Done Enable IDE Read Write Description and Operation The Function r
26. range up to 3 3 ms if an attempt is made to abort a Write function Head movement may take up to a maximum of 80 ms 1 3 2 3 Drive Reset Function For a Drive Reset function the controller directs the selected disk drive to move its head mechanism to cylinder address 000 and reset all active error status lines To the controller the Drive Reset function is the same as a Seek function even to the manner in which the hardware poll logic is used however a Drive Reset function can take much longer than a Seek function to execute The time required to complete a Drive Reset function depends on the physical position of the head mechanism at the time the function is initiated and therefore may take up to a maximum of two seconds 1 3 2 4 Write Lock Function The Write Lock function write protects a selected disk drive until the condition is overridden by operation of the corresponding WT PROT Write Protect switch on the disk drive refer to RK05 Disk Drive Maintenance Manual DEC 00 HRKOS C D The disk drive is automatically write enabled when power is first applied or when the disk drive RUN LOAD switch is set to RUN 1 3 2 5 Write Function For a Write function the controller first performs a normal Seek function When that is completed the next Header word is read and checked for correct cylinder identification cylinder address If the header is correct the controller begins the Write operation when the Sector Counter RKDA 00 through 0
27. sired interrupt level jumper typically BRS should be installed on the M7254 Status Control module see the cover sheet for that module The RK11 crystal clock switch on the M7255 Disk Control module see cover sheet should be positioned to AUTO for the RK11 internal crystal clock The RK11 Controller unit is installed in the following manner 1 Check that wiring is not damaged that module holddown clips are in place and that no modules are loose 2 Install the Unibus cabling or modules according to the RK11 configuration in the PDP 11 system Paragraph 3 3 3 Install the disk drive cable DR BUS in slots A2 and B2 4 Connect the power wiring from the system Power is applied to the RK11 as the system power is turned on The disk drives are powered independently as described in the RKOS Disk Drive Maintenance Manual When power is applied to the RK11 a processor initialize BUS INIT signal from the Unibus initializes the logic 2 6 INSTALLATION TESTING To ensure that the RK11 system is properly installed and operational installation testing is performed by running RK11 diagnostic programs including one pass of the RK11 disk data test MAINDEC 1 1 DSHA PB2 15 minutes of the RKII static test MAINDEC 11 D5HA PB1 and random exerciser MAINDEC 11 DZRKG A PB If performance of these tests fails to reveal any errors it may be assumed that the RK11 is operational and that it has been correctly installed These diagnosti
28. stem 1 2 OPTIONS The RK11 Controller has two options RK11 D and RK11 E both of which are used with the RK05 Disk Drive The RK11 D transfers 16 bit data and the RK11 E transfers 18 bit data Option selection is made by adjusting the jumper configuration as described in Paragraph 2 4 1 3 FUNCTIONAL DESCRIPTION The RK11 Controller and the RKOS Disk Drive form the disk drive system which interfaces with a PDP 11 processor via the Unibus The RK11 is implemented on four functional modules M7254 M7255 M7256 and M7257 and interfaces with the RKOS Disk Drive via a drive bus DR BUS as shown in Figure 1 2 DATA PATHS M7256 STATUS CONTROL M7254 DISK CONTROL M7255 DISK DRIVES BUS ADDRESS LINES BUS CONTROL LINES BUS DATA LINES BUS CONTROL M7257 11 1702 Figure 1 2 RK11 Controller Functional Block Diagram 1 3 1 Disk Drives The RKOS is a moving head disk drive that uses RKO3 KA disk cartridges for data storage Data is stored on both sides of the disk by a pair of movable heads which are always positioned over opposing surfaces of the same cylinder simultaneously Each side of the disk contains 203 y tracks each of which contains 12 y sectors capable of storing 4004 or 25610 data words The sector format consists of 15g words of preamble terminating in a sync bit followed by a one word header 4005 data words a one word checksum and one word of postamble Sector pulses signal the
29. tallation operation and programming information necessary to install and operate the RK11 Moving Head Disk Drive Controller Discussions in the manual deal with general descriptions of the RK11 D and RK11 E Controllers For detailed coverage of the RKOS itself refer to the RKOS Disk Drive Maintenance Manual DEC 00 HRKOS C D Although control signals and data are transferred between the RK11 Controller and the Unibus it is beyond the scope of this manual to cover the operation of the bus itself Detailed information regarding the Unibus may be found in the PDP 11 Peripherals Handbook Reference is occasionally made within this manual to engineering drawings not contained herein These drawings are in the RK11 Moving Head Disk Drive Controller Engineering Drawings Manual a copy of which is supplied with each RK11 Controller That manual contains current RK11 prints updated to the time when the equipment is shipped CHAPTER 1 GENERAL DESCRIPTION 1 1 INTRODUCTION The RK11 D and RK11 E are controllers for rotating mass memories capable of communicating with up to eight daisy chained disk drives Figure 1 1 The system is block oriented but is capable of transferring from 1 to 2 consecutive data words without reinitiation or processor intervention These data transfers occur on the Unibus at the Non Processor Request NPR level of communication RK 11 CONTROLLER TERMINATOR 11 1701 Figure 1 1 RK11 D and RK11 E Disk Drive Sy
30. tions Category Parameters Environmental Limits Temperature 60 to 110 F ambient Operating Relative Humidity 20 to 80 without condensation Operating Vibration Shock To prevent data errors extreme vibrations should be avoided while the disk drives are transferring data Operating Format Drive Format 1 Disk Cartridge Disk Drive 203 Cylinders Disk Drive 2 Disk Surfaces Disk Drive 2 Tracks Cylinder 12 Sectors Track 16 bit RK11 D or 18 bit RK11 E data word 256 9 400 Data Words Sector 3072 9 6000 Data Words Track 614 400 9 Data Words Surface 1 247 232 y Data Words Disk Drive Bit Density Approximately 2200 bpi Double Frequency Unibus NPR Data Word Format Recording Method Data Transfer Path Table 1 3 Related Documents Number Software Disk Operating System Monitor DEC 11 SERA D Programmer s Handbook Hardware PDP 11 Peripherals None Handbook RKOS Disk Drive Maintenance Manual DEC 00 HRK05 C D Also the related PDP 11 System and Processor manuals used with the RK11 Controller 1 6 CHAPTER 2 INSTALLATION 2 1 INTRODUCTION The RK11 Controller system configuration depends on the number of disk drives used in a particular disk drive system Each RK11 can interface up to eight disk drives The first four disk drives are housed in one cabinet the additional disk drives are housed in a second cabinet Each cabinet contains the power controls for the associated
31. us only while the RK11 is bus master during an NPR sequence NOTE Address 777414 is unused 3 3 DATA FORMAT Data is stored on the disk cartridge in groups of 12 sectors per track for both 16 bit RK11 D and 18 bit RK11 E options Each of the twelve disk sectors contains 256 words and is defined by physical sector marks These sector marks generate a sector pulse from the disk drive to the controller Another similar physical disk mark called an index mark defines the starting point for the sequence of sectors All of the sectors are formatted identically in five parts preamble terminated with a sync bit header data checksum and postamble Figure 3 1 SYNC BIT PREAMBLE DE HEADER DATA CHECKSUM POSTAMBLE 15 Words Cylinder 25610 400 Words Sector 1 Word of Zeroes Address 16 Bit or 18 Bit Checksum of Zeroes 1 Word 1 Word The preamble and postamble areas of a sector serve as boundaries before and after the information major states header data and checksum to ensure compatibility between disk drives at the cartridge level despite variations in sector pulse positioning refer to the RK05 Disk Drive Maintenance Manual DEC 00 HRK05 C D The preamble consists of 15 words of zeroes adequate to guarantee that RD GATE will turn on during a known zero data field The disk drive head then waits for the first one to occur sync bit and begins to read with the header word For a Write function the sync bit is automatic
32. would result in what would be essentially an unformatted disk cartridge As a result outside intervention is inhibited until the current sector is completed including Control Reset functions and processor initialize BUS INIT signals This means that such functions as Control Reset Seek and Write Lock which take only a few microseconds to initiate can take as long as 3 3 ms if initiated during a Write function For this reason Seek Drive Reset and Write Lock functions cause an interrupt as soon as the function is initiated provided that RKCS 06 IDE is set 3 5 TIMING CONSIDERATIONS RK11 timing is a consideration in the performance of overlapping Seek or Drive Reset functions because these functions can be initiated on free disk drives while previous Seek or Drive Reset functions are in process on other disk drives Thus up to eight disk drives can be performing a Seek or Drive Reset function simultaneously The hardware poll logic of the Disk Control generates an interrupt when a disk drive has completed the Seek or Drive Reset function RKDS 06 R W S RDY set When a Seek or Drive Reset function has been initiated on the disk drive Address Acknowledge an interrupt request occurs if RKCS 06 IDE is set This process normally requires 1 us but may range up to 3 3 ms if an attempt is made to abort a Write function Head movement however may take as long as 80 ms after which a second interrupt RKCS 13 Search Complete occurs i
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