Manual Cover.tif - Altair 8800 Clone
Contents
1. 15 Loading and Using 4K BASIC from Paper 17 Loading and Using 8K BASIC from lt lt 20 D Loading and Using Disk BASIC from Floppy 015 24 Loading and Using Altair DOS cee eee es 26 F Loading and USING CP M cece eee eee eee eens 29 G Loading and Using Timesharing 5 31 INTRODUCTION The original Altair 8800 is the best computing platform available for reliv ing the birth of the personal computing revolution You will find your new Altair Clone to be the next best thing For most users the Altair computing environment of today is out of neces sity slightly different than the computing environment of the mid 1970s However once familiar with these differences you can follow right along with Altair owners of the 1970s even using original Altair documentation and software to experience first hand the thrill of using these early per sonal computers NEXT STEPS The best way to proceed from here is up to you If you want as real an Altair Experience as possible first understand the hardware configuration of your Altair 8800 Part 1 Altair 8800 Clone Hard ware Specifications second learn how to modify that configuration if needed Part 2 Configuration Monitor then proceed from there using orig inal Altair2. Floppy Performance Current setting Actual Speed 1 Actual Floppy Performance 2 Maximum Floppy Performance x Exit this Menu 6 Baud Rate for Floppy Load Save when transferring floppy data from to the see Floppy Disk Menu a higher baud rate is used to speed up the transfer process The default trans fer rate is 115 2K baud This menu allows selection of a different rate Set Floppy Load Save Baud Rate Current baud rate is 115 2K 1 9600 2 19 2 3 38 4K 4 57 6K 5 76 8K 6 115 2K recommended 7 Single Step Down Options Single step on the 8800 is performed by raising the Single Step switch Pressing down on the Single Step switch does nothing In the 8800b computer however pressing and holding the Single Step switch in the down position au to stepped at a rate determined by jumpers on the front panel board This menu option allows the user to choose similar features for Clone s Single Steps switch The default setting is for this feature to be disabled Single Step Down Options Current setting Disabled 1 Disabled 2 Single Step 3 1 Auto Step per second 4 2 Auto Steps per second 5 4 Auto Steps per second 6 8 Auto Steps per second Exit this Menu 8 Restore Defaults Use the Restore Defaults menu option to restore all options and content to their original values Restore Defaults This operation
3. Terminal Emulator Configuration The TeraTerm terminal emulator is used to duplicate the functionality of a teletype Confirm serial settings of 9600 baud 8 bits no parity one stop bit 8N1 in the Setup gt Serial Port menu in TeraTerm Also confirm that the Transmit Delay fields are both set to zero To load 4K BASIC we must first enter a small program via the front panel called a bootstrap loader The job of the bootstrap loader is to receive a second loader from paper tape called the checksum loader The checksum loader is at the beginning of the BASIC paper tape Once the checksum loader has been read into memory the checksum loader then reads in BASIC from the remainder of the paper tape The code for the bootstrap loader is provided by Altair in the BASIC manual Different versions of the bootstrap loader are required based on the version of BASIC and the type of interface card being used For this demonstration we need the bootstrap loader for the 88 2510 serial board and for 4K BASIC version 3 2 Following is the bootstrap loader code for this combination of BASIC and serial port type Addr Data Addr Data Addr Data Addr Data 000 076 010 041 020 017 030 300 001 003 011 256 021 320 031 351 002 323 012 017 022 333 032 013 003 020 013 061 023 021 033 000 004 076 014 032 024 275 005 025 015 000 025 310 006 323 016 333 026 055 007 020 017 020 027 167 Follow these steps to enter the bootstrap loade
4. for more in formation PART 2 CONFIGURATION MONITOR The Configuration Monitor is used to manage the physical and virtual hardware in the Altair 8800 Clone The monitor is a simple menu driven program built into the Clone Communication with the operator is always via serial port 1 at 9600 baud 8 1 To enter the Configuration Monitor raise and hold the STOP RUN switch in the STOP position then raise the left AUX switch The main menu is displayed System Configuration Monitor 1 7 1 Floppy Disk Menu 2 PROM Menu 3 Serial Port Menu 4 Load BIN File 5 Load HEX File 6 Admin Menu Exit to Altair IMPORTANT Exiting the Configuration Monitor and returning to normal Altair operation should always be performed by backing out of sub menus to the main menu shown above then choosing the Exit to Altair menu option A Floppy Disk Menu The floppy disk menu is used to insert remove and manage floppy disks Flop py disks are byte for byte images of actual Altair floppy disks and are ini tially uploaded to the Clone from a PC Floppy disk content is stored in non volatile RAM inside the Clone and once uploaded is always available when the floppy disk option is selected from the main menu the content of each drive is shown The drive numbers listed are the same drive numbers used with real Altair drives Floppy Drive Content 8 inch floppy drives Drive 0 CP M 2 2 Drive 1 D
5. At this point the PRIME program is in memory and must be saved to a file to create the executable program Immediately use the SAV command to write the program from memory into an executable file You will need to reference ad dress information displayed by the linker after the E command completed 1 Type SAV PRIME 0 and press RETURN 2 At the ENTER LOW ADDRESS prompt type the first number next to the word Data In this case type 17100 and press RETURN 3 At the ENTER HIGH ADDRESS prompt type the second number in the group of three numbers in brackets e g 017177 034654 28 In this case type 34654 and press RETURN 4 At the ENTER START ADDRESS prompt type the first number in the group of three numbers in brackets In this case type 17177 and press RE TURN The SAV command creates the executable file PRIME To run the program simply type PRIME at the DOS prompt and press RETURN More Information Be sure to look at the Altair DOS manual Altair Manuals Altair DOS User s Manual pdf for more information about using Altair DOS 28 F Loading and Using CP M In this demonstration we will boot and demonstrate a few commands running CP M version 2 2 for the Altair Computer Configuration Serial port 1 on the Altair Clone the upper DB 25 connector should be configured as 2510 serial port at octal I O address 20 21 This port serves as the operator
6. s terminal This is a standard Altair configura tion This is also the default Altair Clone configuration for port 1 You can confirm or change the Clone s serial port configuration if needed See Serial Port Menu in Part 2 Configuration Monitor of this manual To boot a floppy disk the Disk Boot Loader DBL PROM was typically in stalled in the Altair Refer to the PROM Menu section in Part 2 Con figuration Monitor to see if this PROM is already installed in the Clone If not follow the instructions to Load New PROM Content and install the file ROMS DBL HEX into one of the empty PROM slots Follow the Insert Floppy instructions in the Floppy Disk Menu section of Part 2 Configuration Monitor to insert the floppy image CPM 2 2 application dsk Either insert the floppy directly into drive 0 or use the Change Drive Assignment menu option after uploading to assign the floppy to drive 0 Once uploaded you do not need to repeat this step unless you over write the floppy with other content Follow these steps to boot CP M 2 2 from floppy disk 1 Turn the power switch on 2 Raise and hold the STOP switch in the STOP position then raise and re lease the RESET switch Finally release the STOP switch This performs a hard reset on the computer and sets all address lights to zero 3 Set switches A15 A8 to the up position and switches 7 to
7. 10 In response to HOW MANY FILES key in 4 and press RETURN 11 In response to HOW MANY RANDOM FILES key in 4 and press RETURN At this point Disk BASIC is up and running You can type an immediate com mand like PRINT 2 2 and press RETURN BASIC will display the answer 4 In this version of BASIC the backspace key performs the normal destructive backspace to which you are accustomed 24 Loading a BASIC Program from Disk Before a floppy disk can be used with BASIC it must be mounted Type MOUNT 0 to tell BASIC to mount the floppy that is in drive zero After the command completes it may take ten or more seconds to complete type FILES to list the files present on the disk You can load a program with the LOAD command or load and run a program with the RUN command The file name specified for either command must be contained in quotes and is case sensitive For example to load the StarTrek game type the following LOAD STARTREK and press RETURN After the program loads you can type LIST to look at the program or RUN to execute the program Loading a BASIC Program through the Console You can also load a BASIC program through the console in the same manner as detailed in the 4K BASIC and 8K BASIC demonstrations This allows you to load new programs from a PC and then save the program to the floppy disk The SAVE command writes a prog
8. Disk Boot Loader DBL PROM was typically in stalled in the Altair Refer to the PROM Menu section in Part 2 Con figuration Monitor to see if this PROM is already installed in the Clone If not follow the instructions to Load New PROM Content and install the hex file ROMS DBL HEX into one of the empty PROM slots Follow the Insert Floppy instructions in the Floppy Disk Menu section of Part 2 Configuration Monitor to insert the floppy image Altair DOS with FORTRAN AltairDOS dsk Either insert the floppy directly into drive 0 or use the Change Drive Assignment menu option after uploading to assign the floppy to drive 0 Once uploaded you do not need to repeat this step unless you over write the floppy with other content Follow these steps to boot Altair DOS from floppy disk 1 Turn the power switch on 2 Raise and hold the STOP switch in the STOP position then raise and re lease the RESET switch Finally release the STOP switch This performs a hard reset on the computer and sets all address lights to zero 3 Set switches 15 8 to the up position and switches 7 to the down position zero This represents the start address of the Disk Boot Loader 177400 octal or FFOO hex 4 Raise the EXAMINE switch to load this address into the processor 5 Set switches 15 13 to the down position This leaves the first four switches 15 12 set to 0001 T
9. Transmit Delay fields are both set to zero In the cassette TeraTerm window confirm serial settings of 9600 baud 8 bits no parity and one stop bit Also confirm that the Transmit Delay fields are both set to zero To load 8K BASIC we must first enter a small program via the front panel called a bootstrap loader The job of the bootstrap loader is to receive a second loader from the tape called the checksum loader The checksum loader is at the beginning of the BASIC tape Once the checksum loader has been read 20 into memory the checksum loader then reads in BASIC from the remainder of the cassette tape The code for the bootstrap loader is provided by Altair in the BASIC manual Different versions of the bootstrap loader are required based on the version of BASIC and the type of interface card being used to load BASIC For this demonstration we need the bootstrap loader for the 88 ACR cassette interface and for 8K BASIC Version 4 0 Following is the bootstrap loader code for this combination of BASIC and serial port type Addr Data Addr Data Addr Data 000 041 010 017 020 300 001 302 011 330 021 351 002 037 012 333 022 003 003 061 013 007 023 000 004 022 014 275 005 000 015 310 006 333 016 055 007 006 017 167 Follow these steps to enter the bootstrap loader 1 2 3 4 5 6 7 8 9 Turn the power switch Raise and hold the STOP switch in the STOP position then rais
10. an Intel hex file File transfer can be aborted by pressing CTRL C or raising the left AUX switch Load New Prom Content Enter PROM Address in hex or return for HEX file Send hex file now initiate simple send file operation from the PC not XMODEM 2 Change Description Change Load Address etc Options 2 6 are fairly self explanatory Note The Change Load Address option does NOT magically relocate already assembled code This option is used if you accidentally typed in the wrong address when initially loading a binary PROM file Serial Port Menu The serial ports on the Altair Clone can be configured in a variety of ways to match the requirements of the software to be run By default port 1 is a 2SIO port Motorola at octal address 020 021 Serial port 2 defaults to an SIO port at address 006 007 the cassette interface port If you pur chased an assembled Clone serial port 1 is the upper DB 25 on the rear panel and serial port 2 is the lower connector If using the optional Audio Cas sette Interface you ll probably want to configure Port 3 to be the cassette I O port SIO at 006 007 300 baud 8N1 instead of Port 2 When the Serial Port Menu option is chosen from the main menu the current serial port settings are displayed as shown below Note The port settings shown are also the default settings Serial Port Settings Port Type I O Rate Other 1 2510
11. documentation and software Original documents and supporting software are under the Support link on the AltairClone com website It is recommended that you download the full Clone support package by clicking on the All Manuals and Software as zip file link then extracting all files to your disk Start your research by looking at the Altair 8800 Operator s Manual Keep in mind that all the manuals contain a mistake or two or more and may send you down the wrong path at times that s part of the fun If you want some help along the the Altair Experience link on the 1 website provides a great list of topics and tutorials you may want to work through on your Altair Clone If you want to quickly set up a few popular Altair demonstrations Part 4 Altair 8800 Demonstrations gives step by step instructions for the follow ing activities e Kill the Bit front panel game e Loading and using 4K BASIC from paper tape Loading and using 8K BASIC from cassette e Loading and using Disk BASIC from floppy disk e Loading and using Altair DOS e Loading and using CP M e Loading and using Timesharing BASIC PART 1 ALTAIR 8800 CLONE HARDWARE SPECIFICATIONS A RAM 64K of RAM with memory protect in 256 byte pages If any PROMs are loaded and enabled the overlaid RAM is replaced by PROM in 256 byte increments B PROM Eight sockets of up to 2K each provide for up t
12. interrupts to the 8080 processor from the vectored interrupt lines VIO VI7 on the Al tair bus The board can also provide 60hz real time clock interrupts while not widely used for most commercial software the VI RTC board is required by MITS Time Sharing BASIC for the Altair If the 88 VI RTC board is not enabled then the default interrupt structure of the Altair PINT with RST7 is used In this case all devices can be tied into the PINT line at the same time as the emulated devices all drive the PINT line with open collector outputs As with the original hardware all boards other than the 88 VI RTC ignore the 8080 interrupt acknowledge cy cle so the 8080 processor sees a RST7 instruction on the bus all data bits high during the interrupt acknowledge cycle Connection of device interrupt outputs to the desired vectored interrupt line on the Altair bus VIO VI0O7 is done in the Interrupt Vector Assignments menu of the Administration Menu See these menus in Part 2 Configuration Monitor for more information G Changing Hardware Configuration If an original Altair owner needed to install a new serial I O card install or remove a PROM or change a baud rate jumper the owner opened the computer and made the required modifications inside the computer In the Altair 8800 Clone these hardware configuration changes are made using menu options in the configuration Monitor See Part 2 Configuration Monitor
13. occupying 92K of 296K total capacity 46 directory entries and 204K bytes remain A gt The programs PCGET and PCPUT make it easy to transfer files from a PC into CP M PCGET and from CP M to a PC PCPUT For example you might start with a program source file found on the internet then use a Windows program like notepad to edit the file when ready to assemble the program use PCGET on the Altair to move the source file from the PC to the Altair then assemble the program using ASM Repeat the edit and transfer cycle until the program works as required PCPUT can then be used for example to save the program listing and or executable file back to the PC You can archive an image of the floppy you ve created back to your PC if de Sired See Save Floppy Content to PC in the Floppy Disk Menu section of Part 2 Configuration Monitor More Information These examples just begin to scratch the surface of the huge collection of software that is available Large repositories of CP M software available on the internet For further reading start with the CP M manual 22 Manual pdf in the Altair Manuals directory 30 G Loading and Using Timesharing BASIC In this demonstration we will boot and use Altair Timesharing BASIC Ver 1 1 Computer Configuration The two serial ports on the back of the Clone can service two user termi nals for Timesharing BASIC
14. the following capabilities is recommended e 8 bit transmission of text files e g paper tape reader e 8 bit reception of text files e g paper tape punch e Per character and or per line delays when transmitting text file e Terminal emulation should include an 8 bit mode in which the 8th bit is ignored assumed by 4K and 8K BASIC Note if the emulator supports 7 bit plus parity mode in which the received parity is ignored this will also work e Support for original XMODEM checksum file send and receive Terminal Emulator On the windows platform The TeraTerm emulator meets all of the requirements listed above TeraTerm is now an Open Source project maintained at http ttssh2 sourceforge jp index html en The version of TeraTerm maintained at the link above is much newer than the version found at the TeraTerm Home Page The latter is not recommended Installing TeraTerm Installation files for TeraTerm are available on the AltairClone com website under the Support link The installation files are also included in the 11 Manuals and Software as a zip file link Follow these steps to install TeraTerm 1 Extract all files from the downloaded zip file 2 Install TeraTerm by running the file teraterm 4 77 exe Note On the Select Components installation page you can de select all optional components 3 Copy the files keyboard cnf baud115k tt1I and baud9600
15. tt1 to the program folder in which TeraTerm was installed 4 the file teraterm ini file to the My Documents folder D Configuring TeraTerm when TeraTerm is launched it loads its configuration from the teraterm ini file it finds in the My Documents folder Step 4 above put a sample con figuration file in the My Documents folder The first time TeraTerm is started you will probably have to select a different COM port under Setup gt Serial Port After choosing the proper COM port save the configuration by choosing Setup gt Save setup and over writing the termaterm ini file in the My Documents folder 13 Using TeraTerm The most commonly used menu options are File gt Send File Sends a file over the serial port with no protocol e g paper tape or cassette or non XMODEM Send File operations in the Configuration Monitor Be sure the Binary checkbox at the bottom of the file dialog box is checked File gt Log Receives a file over the serial port with no protocol e g paper tape or cassette Be sure the Binary checkbox at the bottom of the file dialog box is checked when the file log operation is started a new taskbar tile appears TeraTerm Log when file re ception is complete click on the log taskbar tile and then click the Close button to complete the file receive operation File gt Transfer gt xXmodem Used to send and receive files using t
16. type LIST to look at the program or RUN to execute the program Go ahead and repeat the load process on the second terminal while the first terminal continues to list or run the program Now you ve got two users independently using BASIC at the same time on an Altair 8800 Loading a BASIC Program through the Terminal Serial Port You can also load a BASIC program through a terminal port in the same manner as done in the 4K BASIC and 8K BASIC demonstrations This allows you to load 03205 new programs from a PC and then save the program to the floppy disk However Timesharing BASIC cannot keep up with as fast a serial transfer rate as other versions of BASIC Choose the Setup gt Serial Port menu option in either Ter aTerm window and enter 10 in the msec char field and 300 in the msec line field This slows the character transfer rate to about 100 char acters per second and provides a 0 3 second delay after each line to give BA SIC time to process the line of code Even at this slower rate it is impor tant that there is no activity on the second user terminal while downloading a program in this manner Increase the msec char field to 20 if you experi ence load problems A number of BASIC programs are present in the folders found in the BA SIC BASIC programs folder Follow these steps to try the programs 1 Type NEw followed by RETURN to clear program memory 2 Use the Fil
17. 020 021 9600 2 510 006 007 9600 8 1 3 2510 024 025 9600 Enter Serial Port to Change x to Exit After entering the serial port number to change this menu is displayed Serial Port Menu 1 change Port Type 2 Set Baud Rate 3 Set CTS RTS Usage 4 Set word Length Parity Stop Bits Exit this Menu 1 Change Port Type The Change Port Type option is used to specify the type of Altair serial port assigned to a physical serial port on the Altair Clone The following options are displayed Set Serial Port Type 1 SIO Original serial board Rev 1 2 2510 Motorola 6850 Exit this Menu The SIO port type duplicates operation of the original 88 SIO boards with the status word modification in place These are the most common versions of the SIO board and are referred to as not Rev 0 or Rev 1 in Altair manuals Serial port 1 is at address 0 1 and serial ports 2 and 3 are at address 6 7 matches the SIO port used with the Altair cassette interface The 2510 option duplicates operation of the 88 2SI0 boards which use the Mo torola ACIA as the UART Serial port 1 is at octal address 020 021 port 2 is at octal address 022 023 and port 3 is at octal address 024 025 2 Set Baud Rate Self explanatory 3 Set CTS RTS Usage This option only affects a serial port configured as 2510 port The the 2510 board allows use of handshake lines CTS and RT
18. ALTAIR 8800 CLONE COMPUTER s Manual Operator ALTAIR 8800 CLONE COMPUTER OPERATOR S MANUAL Version 1 8 September 2014 TABLE OF CONTENTS INTRODUCTION Sears Tava eae a oe at eee ean a eae 1 PART 1 ALTAIR 8800 CLONE HARDWARE SPECIFICATIONS 2 PART 2 CONFIGURATION MONITOR eee eee ete ees 4 An Floppy DESK MENU wince 4 tis Ee hehe haley ales Re Dette Deh ee eS 4 Bes PROM oe ch eed Caldera eaten aetna die Acre cae anaes ances Gee 6 MENU gt i See Sad wa a Pee a a glee bate een ea 7 D s lt cLoad BIN Or HEX Pile e s ce whee bedi ied had wie ed asd SOAS ate 9 Administration Menu isope e a ee eee ees 9 PART 3 TERMINAL EMULATOR 02 cee ee eee eee eee eee eee eee eee 13 SOV EEN VOW Bisa dar eee REAL eae ee 13 TeraTerm Terminal 1 13 C instal laing Tera Te CM Ge werk Ae ele 13 D CONTIGUrING T6Ralenm ue a cee a ea ye hee ee ned ae 13 Ei USING TE ral CRMs wes aided aes ae ee al ate ee ae ee ee eee ea eee 14 PART 4 ALTAIR 8800 DEMONSTRATIONS 00 cece cece ence eee 15 A Kill the Bit Front Panel
19. Both serial ports must be configured as 25 0 ports You can confirm or change the serial port configuration as needed See Serial Port Menu in Part 2 Configuration Monitor of this manual If you have the optional Cassette Interface for the Clone it adds a third serial port on the rear panel so you can try three simulatenous users To boot a floppy disk the Disk Boot Loader DBL PROM was typically in stalled in the Altair Refer to the PROM Menu section in Part 2 Con figuration Monitor to see if this PROM is already installed in the Clone If not follow the instructions to Load New PROM Content and install the hex file ROMS DBL HEX into one of the empty PROM slots Follow the Insert Floppy instructions in the Floppy Disk Menu section of Part 2 Configuration Monitor to insert the floppy image file BA SIC Floppy Disk Time Sharing Basic Ver 1 1 dsk Either load the floppy directly into drive 0 or use the Change Drive Assignment menu option after uploading to assign the floppy to drive 0 Once you have uploaded the floppy you do not need to repeat this step unless you over write the floppy with other content Terminal Emulator Configuration The TeraTerm terminal emulator is used to duplicate the functionality of two user terminals First start an instance of TeraTerm to use as the op erator s console and terminal 1 then start a second instance of TeraTerm t
20. OM installed Otherwise BASIC will loop forever and clobber itself while it looks for the end of RAM In response to the TERMINAL WIDTH prompt press RETURN In response to the WANT SIN prompt key in Y and press return 18 At this point 4K BASIC is up and running You can type an immediate command like PRINT 2 2 and press RETURN BASIC will display the answer 4 You can also type in a program and run it Note that in these early versions of BA SIC the underscore character _ is used as the delete key The underscore does not cause a visible delete or backspace The underscore character is echoed but it s up to you to figure out how many characters you have deleted as you type underscores 15 a simple program you can key in RUN 10 FOR I 1 TO 20 20 PRINT LOOP T 30 NEXT I Loading a BASIC Program from Paper Tape BASIC does not have any sort of load command instead programs are typed in by transmitting a paper tape which contains a listing of the pro gram At 110 baud BASIC can keep up with reception of the program However at higher baud rates BASIC needs a delay after each line is received so that it can process and store the line of code before more data comes in For a fast paper tape reader consecutive nulls binary zeros were often punched after each line to provide this delay The nulls were missed while BASIC pro cessed a line of code
21. S On a real 88 2SIO board if the user did not want these signals to affect operation they could be tied active or inactive as needed This menu option allows configuration of how CTS and RTS are used If CTS is set to Not Used CTS is permanently asserted true going into the ACIA If RTS is set to Not Used RTS iS permanently asserted true go ing out of the DB 25 serial port connector when either signal is set to Used the signal passes from to the serial port to the ACIA as expected Set CTS RTS Usage Affects 2510 Ports Only 1 CTS RTS Not Used 2 Only RTS Used 3 Only CTS Used 4 CTS RTS Both Used Exit this Menu 4 Set Word Length Parity Stop Bits This option only affects a serial port configured as an SIO port To config ure word length parity and stop bits on a real 88 SIO board jumper wires were used This menu option allows configuration of these same jumper set tings when this menu option is selected the following menu is displayed Set word Length Parity Stop Bits Affects SIO Ports Only 1 7E2 2 702 3 7 1 4 701 5 8 2 6 8N1 7 8 1 8 801 Exit this Menu Load BIN or HEX File These options provide a convenient cheat to directly load a program or data into Altair memory Files are sent using simple 8 bit transfer not XMODEM If a binary file is sent the load address up to four hex digits must be specified The example
22. SIO board at octal I O address 6 7 This is the standard cassette configuration in the Altair This is also the de fault Altair Clone configuration for port 2 You can confirm or change the Clone s serial port configuration if needed See Serial Port Menu in Part 2 Configuration Monitor of this manual The default baud rate for the cassette SIO port on the Clone is 9600 baud while this is much faster than the 300 baud at which the real cassette in terface operated we recommend using 9600 baud for this demonstration Buffering in the PC s serial port drivers and issues with some USB to Serial adapters can make operation at 300 baud problematic Terminal Emulator Configuration The TeraTerm terminal emulator is used to duplicate the functionality of both the operator s console and the cassette player First start an in stance of TeraTerm to use as the operator s console Then start a second instance of TeraTerm to use as the cassette player You 11 probably re ceive a Cannot Open Serial Port error when you open the second window In the second window go to the Setup gt Serial Port menu and choose the COM port that serial port 2 from the Clone the cassette inter face is connected to In the console TeraTerm window choose Setup gt Serial Port and set the Data field to 7 bits the Parity field to Space and verify the baud rate is 9600 Also confirm that the
23. air This includes files on Altair BASIC disks the Altair DOS disk and on CP M disks A Kill the Bit Front Panel Game Kill the Bit was one of the first games for the Altair It runs on the front panel of the Altair and does not require connection to an external teletype or terminal Following is the assembly language listing of the program Kill the Bit game by Dean McDaniel May 15 1975 Object Kill the rotating bit If you miss the lit bit another bit turns on leaving two bits to destroy Quickly toggle the switch don t leave the switch in the up position Before starting make sure all the switches are in the down position 0000 org 0 0000 210000 1 1 h 0 initialize counter 0003 1680 mvi d 080h up initial display bit 0005 010 00 1 1 b Oeh higher value faster 0008 1A beg d display bit pattern 0009 1A d 8 address lights 000A 1A d 000B 1A d 000c 09 b increment display counter 000D 020800 jnc beg 0010 DBFF in Offh input data from sense switches 0012 AA d exclusive or with 0013 OF rotate display right bit 0014 57 mov d a move data to display reg 0015 c30800 jmp beg repeat sequence 0018 end To run the program it must first be entered into the Altair s memory using the front panel switches The front panel switches are grouped such that data entry from an octal dump
24. assemble another program Type N and press return The assembler outputs a relocatable object file that must be run through the linker before it can be executed Object files are identified by a leading LINK followed by RETURN to the linker The linker s prompt is an asterisk At the prompt type L ECHO 0 to load the relocatable ob ject file for ECHO into memory The default load address is octal 24000 Type at the next prompt to exit the linker At this point the ECHO program is in memory at octal address 24000 Immedi ately use the SAV command to write the program from memory into an executa ble file 1 Type SAV ECHO 0 and press RETURN 2 At the ENTER LOW ADDRESS prompt type 24000 and press RETURN 3 At the ENTER HIGH ADDRESS prompt type 24100 and press RETURN 4 At the ENTER START ADDRESS prompt type 24000 and press RETURN The SAV command creates the executable file ECHO To use the ECHO program you 11 need to start a second instance of TeraTerm connected to serial port 2 on the Altair Clone See the 8K BASIC demonstration for how to setup serial port 2 for the cassette the steps required to use the ECHO program are the same 27 To run the program type ECHO followed by RETURN on the main console Switch to the second TeraTerm window and begin typing Everything typed will be echoed To exit the program
25. atch disk B PROM Menu The PROM menu is used to insert and remove PROMS Eight slots are provided for PROM content Each slot is up to 2K bytes in length PROM content is up loaded from PC in binary bin or Intel Hex hex format Once uploaded PROM content is non volatile PROM content can also be disabled without actu ally removing the PROM so that it can later be re enabled without having to re upload the content from a PC when the PROM Menu option is chosen from the main menu the current content of each PROM slot is displayed as shown below PROM Information Table Num Status Addr Length Description 1 ON FFOO 0100 Disk Boot Loader 2 ON FEOO 0100 Multi Boot Loader 3 ON FDOO 0100 Monitor 4 OFF 0000 0000 5 OFF 0000 0000 6 OFF 0000 0000 7 OFF 0000 0000 8 OFF 0000 0000 Enter PROM Number to Update to exit To load or change the content of a PROM slot enter the slot number The fol lowing menu is displayed 1 Load New PROM Content 2 Change Description 3 Change Load Address 4 Enable the PROM 5 Disable the PROM 6 Remove the PROM Exit this Menu 1 Load New PROM Content The Load New PROM Content option is used to load new content into a PROM slot The PROM data can be uploaded as a binary or Intel hex format file If a binary format is chosen the load address must be specified to four hex digits The example below shows loading PROM content from
26. below shows loading memory from a binary file File transfer can be aborted by pressing CTRL C or raising the left AUX switch Enter load address in hex 0 Send bin file now initiate simple send file operation from the PC not XMODEM E Administration Menu When Admin Menu is selected from the main menu the administration menu is displayed Administration Menu 1 Interrupt Vector Assignments 2 Line Printer Controller 3 Turnkey Module 4 Floppy Drive Type 5 Floppy Performance 6 Baud Rate for Floppy Load Save 7 Single Step Down Options 8 Restore Defaults 9 Update Firmware Exit this Menu 1 Interrupt Vector Assignments The 88 VI RTC Vectored Interrupt Real Time Clock board in the Altair Clone is used to prioritize interrupts to the 8080 processor from the vectored inter rupt lines on the Altair bus VIO VI7 In a real Altair a device s inter rupt output is connected to the desired vector line using a jumper This menu allows specification of that connection when this menu option is selected the present vector assignments for inter rupt sources in the Clone are displayed 88 VI RTC Vectored Interrupt Assignments Device Vector 1 Floppy Drives 0 2 Serial Port 1 2 3 Serial Port 2 2 3 Serial Port 3 3 4 Real Time Clk 1 Enter Device Number to Update x to exit After specifying the device number to update the user can choose a new in terr
27. bit 6 Depress the RUN switch to boot the Altair from the BASIC floppy Immediately upon booting Timesharing BASIC displays version information and then prompts for configuration You 11 want to turn on Caps Lock the sS E keyboard Also to delete characters the BACK SPACE button on the keyboard does not work as expected instead use the DELETE key to the right of the ENTER key As a character is deleted BASIC echoes a followed by the character s deleted for each subsequent delete press In response the Reconfigure Y N L prompt type L for List and press return This displays the current interrupt assignments You 11 notice the disk is at level 0 Chighest priority and the 60hz real time clock inter rupt is at level 1 the next highest priority Interrupt levels 2 through 5 each have two serial port devices assigned to them For example the values 16 and 18 at level 2 are the 1 0 address of the two terminals assigned to in terrupt level 2 These are the same I O addresses of the two serial ports used in the Altair Clone The Reconfigure L prompt is displayed again This time type and press return to continue with initialization 1 In response to the MEMORY SIZE prompt press RETURN to let BASIC de termine the amount of RAM present 2 In response to the NUMBER OF USERS prompt type 2 and press RETURN 3 In response to TERMINAL ADDRESS
28. diting a Source File Files staring with amp are typically source files To view or edit a source file run the editor by typing EDIT filename where filename is the name of the source file without the leading amp For example to edit the source file for PRIME amp PRIME type EDIT PRIME 0 and press return The trailing zero is the drive number the file is on If you forget to specify the drive num ber you will be prompted to enter the drive number on a separate line The editor s prompt is an asterisk To view a file s full content type p for Print and press RETURN To exit the editor without saving changes type Q and press RETURN To exit and save changes type E followed by RE TURN Refer to the Altair DOS user s manual for more information about using the editor see More Information below Assembling and Linking an Assembly Language Program The file amp ECHO is the source file for an assembly language program that echoes typed characters back to the screen through serial port 2 not the main console port You can view the source file by typing EDIT ECHO 0 and then pressing P at the editor s prompt as detailed above for PRIME To assemble the program type ASM and press RETURN When prompted for the file name type ECHO 0 without the leading amp and press RETURN The as sembler runs then prompts if you want to
29. e gt Send File menu option in TeraTerm to browse to and transmit the BASIC program you want to load 3 The program will display on the screen as BASIC reads it in The file transmit dialog box will close before the actually finishes trans mitting the program This is normal Once a program is in memory you can save the program to floppy disk using the SAVE command For example to save a program in memory to the file name NEWPROG type the following SAVE NEWPROG and press RETURN to write the program to the floppy disk If you have modified a floppy with new content and you want to archive the floppy to your PC follow the Save Floppy Content to PC instructions in the Floppy Disk Menu section of Part 2 Configuration Monitor to write the floppy image to a file on your PC More Information Be sure to look at the Timesharing BASIC manual Altair Manuals MITS Time sharing BASIC pdf for more information Note The manual is for Timesharing BASIC version 2 but the version running on the computer is version 1 1 so there are a few differences between the manual and the running version 33
30. e and re lease the RESET switch Finally release the STOP switch This performs a hard reset on the computer and sets all address lights to zero Put the first data byte in switches 7 through 0 then raise DEPOSIT Put the data for the next address in switches 7 through 0 then depress DEPOSIT NEXT Repeat step 4 until all bytes have been entered Raise and release RESET to force all address lights back to zero verify the data shown on lights D7 through DO matches the data byte for the current address If the value is correct go to step 9 otherwise go to step 8 Put the correct value in switches 7 through 0 then raise DEPOSIT Depress EXAMINE NEXT 10 Repeat steps 7 through 9 to validate entry of the entire program Once the bootstrap loader is entered and verified we re almost ready to load BASIC But first we must set the run address to zero and then set the front panel ports 1 2 3 4 sense switches to tell the checksum loader and BASIC the type of serial in use for the console device and for the load device Set all address switches to zero Raise EXAMINE to set all address lights the 8080 program counter to zero Raise 12 to the up position This tells the checksum loader and BASIC that a 2510 serial board with one stop bit is the console interface Raise 9 8 to the up position This tells the checksum loader that the cassette interface is being used to load BASIC Now we r
31. e finally ready to actually load BASIC eR amp 1 Depress RUN to run the bootstrap loader If the loader was entered cor rectly address lights 10 9 A4 A0 should be 2 Use the File gt Send File menu option in the cassette TeraTerm window to transmit the cassette tape image to the Altair Browse to and select the file 8K Basic Ver 4 0 tap which is located in the Paper Tape and Cassette folder inside the BASIC folder Be sure the binary check box at the bottom of the send file dialog is checked 3 Loading BASIC will only take about eight seconds at 9600 baud instead of about four minutes at 300 baud Once loaded BASIC initializes and prompts the user for memory size 4 Turn on Caps Lock on the keyboard 5 In response to the MEMORY SIZE prompt press RETURN to let BASIC de termine the amount of RAM present 6 In response to the TERMINAL WIDTH prompt press RETURN 7 In response to the WANT SIN prompt key in Y and press return At this point 8K BASIC is up and running You can type an immediate command like PRINT 2 2 and press RETURN BASIC will display the answer 4 You can also type in a program and run it Note that in these early versions of BA SIC the underscore character _ is used as the delete key The underscore does not cause a visible delete or backspace The underscore character is echoed but it s up to you to figure o
32. floppy image BA SIC Floppy Disk Games on 300 5 F dsk Either load the floppy directly into drive 0 or use the Change Drive Assignment menu option after up loading to assign the floppy to drive 0 Once you have uploaded the flop py you do not need to repeat this step unless you over write the floppy with other content Follow these steps to boot Altair BASIC from floppy disk 1 Turn the power switch on 2 Raise and hold the STOP switch in the STOP position then raise and re lease the RESET switch Finally release the STOP switch This performs a hard reset on the computer and sets all address lights to zero 3 Set switches 15 8 to the up position and switches 7 to the down position zero This represents the start address of the Disk Boot Loader 177400 octal or FFOO hex 4 Raise the EXAMINE switch to load this address into the processor 5 Set switches 15 13 to the down position This leaves the first four switches 15 12 set to 0001 This tells BASIC the console terminal is connected to a 2SIO board with one stop bit 6 Depress the RUN switch to boot the Altair from the BASIC floppy 7 In response to the MEMORY SIZE prompt press RETURN to let BASIC de termine the amount of RAM present 8 In response to the LINEPRINTER prompt key in capital letter oh and press RETURN 9 In response to HIGHEST DISK NUMBER key in 2 and press RETURN
33. he XMODEM protocol The Configuration Monitor uses XMODEM transfers to exchange floppy disk content with the Clone Also the CP M utilities PCGET and PCPUT use the XMODEM protocol to transfer files between the Al tair and a PC Setup gt Serial Port Used to change baud rate bits parity delay per character and line etc The following keyboard macros are enabled if step 3 was done correctly during installation CTRL 1 changes to 115 200 baud for transferring floppy content CTRL 9 changes to 9 600 baud default baud rate Note The current baud rate is visible in the title bar of the TeraTerm win dow 14 PART 4 ALTAIR 8800 DEMONSTRATIONS This section contains step by step instructions for several popular Altair demonstrations These demonstrations assume you have downloaded the support package from the AltairClone com website Click on the Support link at the top of any page then click on the All Manuals and Software as zip file link Extract all files from the zip file to your computer These demonstrations just scratch the surface of what can be done and learned with your Altair 8800 Clone Be sure to dig through the documentation and software provided in the downloaded support package you will find a wealth of useful manuals and software Keep in mind that some of the software is hidden on Altair floppy disk images that can be seen only after the floppy is loaded on to the Alt
34. his tells Altair DOS the console ter minal is connected to a 2510 board with one stop bit 6 Depress the RUN switch to boot from the Altair DOS floppy 7 Turn on Caps Lock on the keyboard 8 In response to the MEMORY SIZE prompt press RETURN to let Altair DOS determine the amount of RAM present 9 In response to the INTERRUPTS prompt key in Y must be capital and press RETURN 10 In response to HIGHEST DISK NUMBER key in 2 and press RETURN 11 In response to HOW MANY FILES key in 4 and press RETURN 12 In response to HOW MANY RANDOM FILES key in 4 and press RETURN At this point Altair DOS is up and running The DOS prompt is a period 11 commands must be in upper case when backspace is typed to correct an error Altair DOS echoes each character as it is deleted 2 26 Before the content of the floppy disk can be used the disk must be mounted Type MNT 0 to mount the floppy on drive 0 when the command completes could take ten more seconds type DIR 0 at the prompt to see a direc tory of files on the disk Running a Program from Disk Files starting with are executable files To run an executable file sim ply type the filename without the leading and press RETURN For example the program PRIME computes and displays prime numbers between 1 and 200 To run the program type PRIME and press RETURN E
35. ights the 8080 program counter to zero 3 Depress RUN to run the program To start the game over raise and release RESET To change the rate at which the light moves change the byte at address 6 from 016 to a different value Higher values move the light faster lower values move the light slower 16 B Loading and Using 4K BASIC from Paper Tape In this demonstration we will load 4K BASIC Version 3 2 from paper tape In the mid 1970 s a teletype connected to single serial port on the Altair would have served as both the console and paper tape reader we will dupli cate this configuration using a terminal emulator on a PC as both the console and paper tape reader Computer Configuration For this exercise serial port 1 on the Altair Clone the upper DB 25 connector should be configured as 2510 port at octal I O address 20 21 This is a standard Altair configuration This is also the default Altair Clone configuration You can confirm or change the Clone s serial port configuration if needed See Serial Port Menu in Part 2 Configuration Monitor of this manual The default baud rate for the serial port on the Clone is 9600 baud while this is much faster than the 110 baud at which a real teletype operates we recommend using 9600 baud for this demonstration Buffering in the PC s serial port drivers and issues with some USB to Serial adapters can make operation at 110 and 300 baud problematic
36. ile TEST DAT to NAMES DAT type REN NAMES DAT TEST DAT at the command prompt The program PIP Peripheral 29 Interchange Program allows copying of files on the same disk between disks between devices between devices and disks etc The program SURVEY displays information about the system including memory usage I O port usage and disk space The program Word Master is easy to use full screen text editor The program LADDER is a precursor to games like Super Mario The program is Microsoft BASIC 80 Version 5 21 ASM and MAC are as semblers from Digital Research Inc the author of CP M M80 and L80 are Microsoft s 8080 assembler and linker Assembling and Running Programs The CP M disk used in this demonstration has very little free space available for program development You can create a more useful development disk by de leting the files that aren t required For example here is a directory list ing of a disk tailored to use the ASM and MAC assemblers This disk leaves 204K bytes available for program development A gt LS Name Ext Bytes Name Ext Bytes Name Ext Bytes Name Ext Bytes ASM COM 8K LS COM 4K PIP COM 8K WM COM 12K DDT COM 6K MAC COM 12K STAT COM 6K WM HLP 4K DUMP COM 2K NSWP COM 12K SUBMIT COM 4K XSUB COM 2K FORMAT COM 2K PCGET COM 2K SURVEY COM 2K LOAD COM 2K PCPUT COM 2K VIEW COM 2K 18 File s
37. irms the operation and prompts for the baud rate change The PC baud rate should be set to 115 200 baud after which the XMODEM receive operation can be initiated on the If using TeraTerm a convenient shortcut is pressing CTRL 1 to set the baud rate to 115 200 baud The new baud rate can be seen in the ti tle bar when the transfer completes the user is prompted to return the PC baud rate to 9600 baud If using TeraTerm a convenient shortcut is pressing CTRL 9 to return the baud rate to 9600 baud The new baud rate can be seen in the Ter aTerm title bar This sequence is shown below Save content of Altair DOS to the PC Are you sure y n y Step 1 Set terminal computer baud rate to 115 2 Step 2 Start XMODEM file RECEIVE after setting the new baud rate XMODEM transfer occurs here Return terminal computer to 9600 baud then press return If the XMODEM transfer must be aborted first abort the Clone transmission by raising and releasing the left AUX switch then stop the receive operation on the PC end 4 Change Floppy Description Use this menu option to change the description of a drive s content This can also be used to eject a floppy you re no longer using by changing the de scription to Scratch Disk any similar description to indicate the drive is free to use From the Altair s perspective a floppy disk is still present in the drive just consider it a blank or scr
38. is easiest Following is a dump of each byte of the program in octal wise Addr Data Addr Data Addr Data 000 041 010 032 020 333 001 000 011 032 021 377 002 000 012 032 022 252 003 026 013 032 023 017 004 200 014 011 024 127 005 001 015 322 025 303 006 016 016 010 026 010 007 000 017 000 027 000 Follow these steps to enter the program 1 Turn the power switch on 2 Raise and hold the STOP switch in the STOP position then raise and re lease the RESET switch Finally release the STOP switch This performs a hard reset on the computer and sets all address lights to zero 3 Put the first data byte in switches 7 through 0 then raise DEPOSIT 4 Put the data for the next address in switches 7 through 0 then depress DEPOSIT NEXT 5 Repeat step 4 until all bytes have been entered 6 Raise and release RESET to force all address lights back to zero 7 Verify the data shown on lights D7 through DO matches the data byte for the current address If the value is correct go to step 9 otherwise go to step 8 8 Put the correct value in switches 7 through 0 then raise DEPOSIT 9 Depress EXAMINE NEXT 10 Repeat steps 7 through 9 to validate entry of the entire program Once the program is entered you re ready to play Kill the Bit Read the in structions in the program listing above then follow the steps below to run the game 1 Set all address switches to zero 2 Raise EXAMINE or raise RESET to set all address l
39. isk BASIC Games Drive 2 Altair DOS Choose Drive Number to Update x to exit when a drive number is selected the following menu is displayed Floppy Drive Menu 1 Change Drive Assignment 2 Insert Floppy Load Content from PC 3 Save Floppy Content to PC 4 change Floppy Description x Exit this Menu 1 Change Drive Assignment The change Drive Assignment option is used to change which drive a floppy disk is in This is typically used to put a different disk into drive zero for booting The selected disk is swapped with the disk presently in the des tination drive number 2 Insert Floppy The Insert Floppy option is used to load new content into a drive The floppy disk image is uploaded from a PC using the XMODEM protocol original XMODEM with 128 byte blocks and checksum Compatible disk images files typi cally have a dsk extension and are 330K or 75K in size 8 inch minidisk The floppy image transfer is done at a higher baud rate to reduce the trans fer time The default transfer rate is 115 200 baud This rate can be changed in the Baud Rate for Floppy Load Save option in the Admin menu Upon selecting the Insert Floppy option the monitor confirms the operation and prompts for a description of the new disk The PC baud rate should then be set to 115 200 baud after which the XMODEM send operation can be initiated on the Pc If using TeraTerm a convenient sho
40. m Setup gt Serial Port menu to restore 8N1 and to set the transmit delay back to zero This helps avoid problems and confusion with the next exercise you may try More Information Be sure to look at the 1977 BASIC manual Altair Manuals BASIC Manual 77 pdf for more information about 8K BASIC 23 D Loading and Using Disk BASIC from Floppy Disk In this demonstration we will boot and use Altair Disk BASIC version 5 cifically version 300 5 F Computer Configuration Serial port 1 on the Altair Clone the upper DB 25 connector should be configured as 2510 serial port at octal I O address 20 21 This port serves as the operator s terminal This is a standard Altair configura tion This is also the default Altair Clone configuration for port 1 You can confirm or change the Clone s serial port configuration if needed See Serial Port Menu in Part 2 Configuration Monitor of this manual To boot a floppy disk the Disk Boot Loader DBL PROM was typically in stalled in the Altair Refer to the PROM Menu section in Part 2 Con figuration Monitor to see if this PROM is already installed in the Clone If not follow the instructions to Load New PROM Content and install the file ROMS DBL HEX into one of the empty PROM slots Follow the Insert Floppy instructions in the Floppy Disk Menu section of Part 2 Configuration Monitor to insert the
41. n about 4K BASIC 19 Loading and Using 8K BASIC from Cassette In this demonstration we will load 8K BASIC Version 4 0 from a cassette tape file The 88 ACR cassette interface for the Altair consisted of an audio modulator demodulator board that connected to a standard cassette recorder and to an 88 SIO serial interface board The SIO board provided the data in terface with the Altair bus The digital content present on the cassette tape for loading BASIC was the same data and format as used on paper tape In this exercise we will not use the cassette player and tape itself but instead send the data contained on the cassette through the same SIO board and port addresses as used by the 88 ACR cassette interface the Altair won t know the difference A separate serial port is used to connect to the opera tor s terminal Note If you have the optional Audio Cassette Interface for the Altair Clone this same demonstration is present in the Cassette Interface User s Manual using a real cassette and tape player Computer Configuration Serial port 1 on the Altair Clone the upper DB 25 connector should be configured as 2510 serial port at octal I O address 20 21 This port serves as the operator s terminal This is a standard Altair configura tion This is also the default Altair Clone configuration for port 1 The cassette data comes in on serial port 2 the lower DB 25 connector which should be configured as an
42. o 16K of PROM Loaded and enabled PROMs overlay and replace RAM in 256 byte increments A feature pre sent in the 8800b Turn Key computer to disable PROM order to re enable RAM can be turned on if desired See Administration Menu in Part 2 figuration Monitor for more information Serial Ports Two serial ports are wired to DB 25 connectors on the rear of the computer The port types can be configured to match original Altair hardware as shown below The optional Audio Cassette Interface adds the third serial port The first row illustrates the default configuration Serial Port 3 Serial Port 1 Top Connector Serial Port 2 Bottom Connector from Cassette Intf First port from 88 2510 board at I O address oc tal 20 21 88 SIO port at I O ad dress 6 7 the Altair cassette serial port First port from a second 88 2510 board at I O ad dress octal 24 25 88 SIO port at I O ad dress O 1 Second port from 88 2SI0 board at I O address oc tal 22 23 88 SIO port at I O ad dress 6 7 the Altair cassette serial port The serial ports are wired as follows Pi Signal 5 2 XMT from Terminal out to Clone Cin 3 RCV to Terminal Cin from Clone out 4 RTS from Terminal out to Clone CTS in 5 CTS to Terminal Cin from Clone RTS out 7 Signal Ground By default pin 4 RTS which becomes CTS inside the Clone is always asserted inside the Clone and therefo
43. o use as terminal 2 You 11 probably receive a Cannot Open Serial Port error when you open the second TeraTerm window In the second window go to the Setup gt Serial Port menu and choose the COM port that second se rial port from the Clone is connected to In the terminal 1 TeraTerm window choose Setup gt Serial Port and set the Data field to 7 bits and the Parity field to Space This step is not critical but it prevents garbage characters from displaying at the end of each line during initialization These garbage characters occur for the same reasons detailed in the 4K BASIC demonstration Follow these steps to boot Altair Timesharing BASIC from floppy disk 1 Turn the power switch on 2 Raise and hold the STOP switch in the STOP position then raise and re lease the RESET switch Finally release the STOP switch This performs a hard reset on the computer and sets all address lights to zero 3 Set switches A15 A8 to the up position and switches 7 to the down position zero This represents the start address of the Disk Boot Loader 177400 octal or FFOO hex 4 Raise the EXAMINE switch to load this address into the processor 5 Set switches 15 13 11 9 to the down position This leaves the first four switches 15 12 and the second four switches A11 A8 each set to 0001 This tells BASIC the console terminal is connected to 2SIO board with one stop
44. port 2 See Line Printer controller in the Administration Menu sec tion of Part 2 Configuration Monitor for more information E Floppy Drives The Altair Clone provides three floppy drives that duplicate the function ality of the original Altair 8 inch floppy drives or the Altair Minidisk 5 25 inch drive Floppy storage is implemented using non volatile RAM inside the Altair Clone Since physical floppy disks and drives are not present in serting a floppy disk is done by uploading a floppy image from a PC to the Clone Conversely a floppy image on the Clone can be saved back to a PC for archiving Once uploaded to the Clone floppy disk content is non volatile and further data exchange with a PC is not required to use the floppy drives Floppy disks can be swapped between the three drives to put a different disk into drive zero to boot for example without having to connect to a PC The Con figuration Monitor makes floppy disk handling simple See Floppy Disk Menu in Part 2 Configuration Monitor for more information F Interrupts and the 88 VI RTC Board Interrupts in the Altair 8800 Clone can be generated by the serial ports 2510 and or SIO for both transmit and receive the floppy disk controller sector true interrupt at the start of each sector by the real time clock present on the 88 VI RTC board The 88 VI RTC Vectored Interrupt Real Time Clock board prioritizes
45. r 1 Turn the power switch on 2 Raise and hold the STOP switch in the STOP position then raise and re lease the RESET switch Finally release the STOP switch This performs a hard reset on the computer and sets all address lights to zero 3 Put the first data byte in switches 7 through 0 then raise DEPOSIT ely 4 5 6 7 8 9 Put the data for the next address in switches 7 through 0 then depress DEPOSIT NEXT Repeat step 4 until all bytes have been entered Raise and release RESET to force all address lights back to zero verify the data shown on lights D7 through DO matches the data byte for the current address If the value is correct go to step 9 otherwise go to step 8 Put the correct value in switches 7 through 0 then raise DEPOSIT Depress EXAMINE NEXT 10 Repeat steps 7 through 9 to validate entry of the entire program Once the bootstrap loader is entered and verified we re almost ready to load the BASIC paper tape But first we must set the run address to zero and then set the front panel sense switches to tell the checksum loader and BASIC the type 1 2 3 of serial port that is in use Set all address switches to zero Raise EXAMINE to set all address lights the 8080 program counter to zero Raise All and 10 to the up position This tells the checksum loader and BASIC that you are using a 2510 serial board with one stop bit to load BASIC and to as yo
46. ram in memory to the floppy disk For exam ple to save a program in memory to the file name NEWPROG type the follow ing SAVE NEWPROG and press RETURN to write the program to the floppy disk If you have modified a floppy with new content and you want to archive the floppy to your PC follow the Save Floppy Content to PC instructions in the Floppy Disk Menu section of Part 2 Configuration Monitor to write the floppy image to a file on your PC More Information Be sure to look at the 1977 BASIC manual Altair Manuals BASIC Manual 77 pdf for more information about all versions of Altair BASIC 25 E Loading and Using Altair DOS In this demonstration we will boot and use Altair DOS version 1 0 Announced in 1975 but not delivered until 1977 Altair DOS was never widely adopted By the time it was released the much easier to use and more flexible CP M operating system was rapidly gaining popularity Computer Configuration Serial port 1 on the Altair Clone the upper DB 25 connector should be configured as 2SIO serial port at octal I O address 20 21 This port serves as the operator s terminal This is a standard Altair configura tion This is also the default Altair Clone configuration for port 1 You can confirm or change the Clone s serial port configuration if needed See Serial Port Menu in Part 2 Configuration Monitor of this manual To boot a floppy disk the
47. rams into 8K BASIC For more informa tion on why the following steps work see Loading a BASIC Program from Paper Tape in the 4K BASIC demonstration Choose the Setup gt Serial Port menu option in the console TeraTerm window and enter 300 in the msec line field This provides a 0 3 second delay after each line to give BASIC time to process the line of code You may have to increase the delay to 500 msec line to load larger programs since the line encoding process gets slower as the program size increases Program files compatible with 8K BASIC are present in the 4K BASIC 8K BA SIC and the Games Creative Comp folders inside the BASIC BASIC pro grams folder Note most of the programs in the Games folder will work in 8K BASIC but not all of them The 72 character line length limit in 8K BASIC is typically the culprit Follow these steps to try the programs 1 Type NEW followed by RETURN to clear program memory 2 Use the File gt Send File menu option in TeraTerm to browse to and transmit the BASIC program you want to load 3 The program will display on the screen as BASIC reads it in The file transmit dialog box will close before the PC actually finishes trans mitting the program This is normal 4 Once the program is loaded type RUN followed by RETURN to execute the program 5 Repeat steps 1 5 to try another program when you are finished use the TeraTer
48. re does not need to be connected on the DB 25 if active handshaking is not used RTS is not present or used on Port 3 By default pin 5 CTS which 15 driven from RTS inside the Clone is always asserted in case an asserted handshake signal is required by the peripheral device CTS 15 not present or used on Port 3 The on the 88 2SIO board supports programmed hardware handshaking If your applications requires this feature the ACIA s handshake lines can be configured to be fully active See Set CTS RTS Usage in the Serial Port Menu section of Part 2 Configuration Monitor for more information D Line Printer Port The Altair Clone implements the Altair 88 LPC line printer interface board This board is supported by Altair BASIC Altair DOS CP M 1 4 and CP M 2 2 when prompted for the printer type in Altair BASIC or Altair DOS choose capital letter oh to select the 88 LPC interface aes In the Altair Clone data sent to the 88 LPC is transmitted out serial port 2 which in turn can be connected to a terminal emulator window to view printer output or connected directly to a serial printer Normal serial port functions of port 2 still work when routing 88 LPC output through the port For example serial port 2 can be used as the cassette interface to load and save programs and to also see line printer output If needed the 88 LPC can be disabled if it interferes with your use of se rial
49. return to the console window and type CTRL C Compiling and Linking a FORTRAN Program Microsoft s FORTRAN compiler F80 macro assembler M80 and linker L80 are present on the Altair DOS disk Note that these programs do not use the leading character file naming convention that Altair DOS does so when a source file name is specified the leading amp must be included as part of the file name Similarly these programs do not precede object file names with an but instead concatenate REL to the end of the file name To compile the PRIME program type F80 to start the FORTRAN compiler At the prompt type PRIME amp PRIME and press RETURN to compile the program the leading amp must be specified for the source file when the prompt returns type CTRL C to exit the compiler The object file name output by the compiler consists of the first five characters of the specified object file name PRIME concatenated with the REL extension at the end PRIMEREL To link the PRIME program type L80 to start the linker At the prompt type the object file name PRIME followed by RETURN to load the object file The REL extension is assumed if not specified when the prompt re turns type E and RETURN to link the object file with the FORTRAN librar ies load the executable into memory and exit to Altair DOS This step may take a while
50. rtcut is pressing CTRL 1 to set the baud rate to 115 200 baud The new baud rate be seen in the title bar when the transfer completes the user is prompted to return the PC baud rate to 9600 baud If using TeraTerm a convenient shortcut is pressing CTRL 9 to return the baud rate to 9600 baud The new baud be seen the Ter aTerm title bar This sequence is shown below Insert Floppy Load Content This will over write Altair DOS you sure y n Enter floppy description New Disk Step 1 Set terminal computer baud rate to 115 2K Step 2 Start XMODEM file SEND after setting the new baud rate XMODEM transfer occurs here Return terminal computer to 9600 baud then press return If the XMODEM transfer must be aborted first stop the transfer from the PC end then abort the Clone s reception by raising and releasing the left AUX switch 3 Save Floppy Content to PC This menu option is used to write a floppy disk image back to a PC for ar chiving The floppy disk image is downloaded to the PC using the XMODEM pro tocol original XMODEM with 128 byte blocks and checksum The floppy image transfer is done at a higher baud rate to reduce the transfer time The de fault transfer rate is 115 200 baud This rate can be changed in the Baud Rate for Floppy Load Save option the Admin menu Upon selecting the Save Floppy option the monitor conf
51. ter file name specified in the CLOAD com mand H or L then loads that program You 11 find that even at 9600 baud the CLOAD command can keep up without re quiring transmit delays in the file transfer Since the program was saved to 2x tape as a RAM image of the program BASIC does not have to encode the program as it is received Pretty impressive speed for an old computer and software Saving a BASIC Program to Cassette Tape Programs can be added to an existing tape file or written to a new file as follows 1 Use the File gt Log menu option in the cassette TeraTerm window to specify a file to write as the cassette tape Check the Binary check box Check the Append check box if you want to add to an existing cassette tape Click Save to start the file save process 2 Type CSAVE x in BASIC where x is a one character file name that is different than any other file name on the tape 3 After the CSAVE operation completes and BASIC displays OK click on the TeraTerm Log icon on the windows taskbar to display the TeraTerm Log dialog box Choose Close to finish the file save operation Loading a BASIC Program through the Console The majority of BASIC programs you 11 find not in 8K compatible cassette format but instead are provided as a simple ASCII listing of the program The same technique used to load programs through the console serial port in 4K BASIC can be used to load these prog
52. the down position zero This represents the start address of the Disk Boot Loader 177400 octal or FFOO hex 4 Raise the EXAMINE switch to load this address into the processor 5 Depress the RUN switch to boot the Altair from the BASIC floppy CP M displays a welcome message and then displays the command prompt A gt Commands and file names are not case sensitive The backspace key performs the normal destructive backspace to which you are accustomed To see a directory of files on the disk type DIR followed by RETURN Files with an extension of COM are executable programs To run a program simply type its name without the COM extension at the command prompt For exam ple type LS and RETURN to run the program LS COM This program displays a directory listing in sorted order and includes file size information To view the contents of a source or other printable file use the TYPE com mand followed by the file name to display For example key in TYPE MITSCNVT TXT to display the content of the file MITSCNVT TXT Use CTRL S to successively pause and resume display of screen output The program VIEW also displays file content but pauses after each screen of content The pro gram DUMP can be used to display the content of non printable files The ERA command is used to erase a file The REN command is used to re name a file For example to rename the f
53. then when receiving again BASIC ignored the nulls un til valid data at the start of the next line was received Rather than inserting nulls after each line in the program source files Ter aTerm can be configured to delay after each line of code to accomplish the same effect Go to the Setup gt Serial Port menu in TeraTerm and enter 300 in the msec line field This provides a 0 3 second delay after each line to give BASIC time to process the line of code A number of BASIC programs compatible with 4K BASIC are present in the folder BASIC BASIC programs 4K BASIC Follow these steps to try the programs 1 Type NEW followed by RETURN to clear program memory 2 Use the File gt Send File menu option in TeraTerm to browse to and transmit the BASIC program you want to load 3 The program will display on the screen as BASIC reads it in The file transmit dialog box will close before the PC actually finishes trans mitting the program This is normal 4 Once the program is loaded type RUN followed by RETURN to execute the program 5 Repeat steps 1 5 to try another program when you are finished use the TeraTerm Setup gt Serial Port menu to restore 8N1 and to set the transmit delay back to zero This helps avoid problems and confusion with the next exercise you may try More Information Be sure to look at the 1975 BASIC manual Altair Manuals BASIC Manual 75 pdf for more informatio
54. type in 16 and press RETURN 4 In response to REGION SIZE TYPE in 18K and press RETURN 5 In response to TERMINAL ADDRESS type in 18 and press RETURN 6 In response to REGION SIZE TYPE in 18K and press RETURN 7 In response to the MOUNT PASSWORD prompt key in PASSWORD and press RETURN The password can be any string up to eight characters in length and is required to mount or dismount a disk At this point Timesharing BASIC displays version information once again but this time on both user terminals You can type an immediate command like PRINT 2 2 and press RETURN on either terminal window and BASIC will display the answer Loading a BASIC Program from Disk Before a floppy disk can be used with BASIC it must be mounted Type MOUNT 0 on either terminal to tell BASIC to mount the floppy that is in drive ze ro BASIC will ask for the MOUNT PASSWORD Respond with the password pro vided in step 7 above After the command completes it may take ten or more seconds to complete type FILES to list the files present on the disk You can load a program with the LOAD command or load and run a program with the RUN command The file name specified for either command must be contained in quotes and is case sensitive For example to load the StarTrek game type the following LOAD STARTREK and press RETURN After the program loads you can
55. upt vector number 0 7 for the device VIO is the highest interrupt pri ority VI7 is the lowest priority For the Real Time Clock only a D for Disabled can be entered as a vector number This disables interrupts from the RTC even if 8080 software enables them 2 Line Printer Controller Altair BASIC Altair DOS CP M 1 4 and CP M 2 2 all support the Altair 88 LPC line printer interface when prompted for the printer type in Altair BASIC or Altair DOS choose capital letter oh to select the 88 LPC interface In the Altair Clone data sent to the 88 LPC can be routed to serial port 2 which in turn can be connected to a terminal emulator window to view printer output or connected directly to a serial printer This menu option allows the user to enable or disable this feature The default setting is for the 88 LPC output to be enabled Note that normal serial port functions of port 2 still work when routing 88 LPC output through the port For example serial port_2 can be used as the cassette interface to load and save programs and to also see line printer output Line Printer Controller Current setting Line Printer Enabled on Serial Port 2 1 Enable Line Printer on Serial Port 2 2 Disable Line Printer Output Exit this Menu 3 Turnkey Module The Altair Turnkey board can be installed or removed with this menu The Turnkey Module provides auto start to_a specified address typicall
56. ur console Now we re finally ready to actually load BASIC 1 2 3 4 5 6 7 Depress RUN to run the bootstrap loader If the loader was entered rectly address lights 12 and 4 0 should be on Transmit the paper tape image by using the File gt Send File menu op tion in TeraTerm Browse to and select the file 4K Basic Ver 3 2 tap which is located in the Paper Tape and Cassette folder inside the BASIC folder Be sure the binary checkbox at the bottom of the send file dialog is checked when sending a paper tape file Loading BASIC will only take about five seconds at 9600 baud instead of seven minutes at 110 baud Once loaded BASIC initializes and prompts the user for memory size The prompt may look a bit garbled as shown MEMORY 5174 This occurs because 4K BASIC uses bit 7 to store additional informa tion However because teletypes ignored bit 7 this did not cause a problem we can duplicate this effect in TeraTerm by choosing Setup gt Serial Port and setting the Data field to 7 bits and setting the Parity field to Space Note These settings must be returned to 8N1 if you need to start over and send the paper tape file once again Turn on Caps Lock on the keyboard In response to the MEMORY SIZE prompt key in 20000 and press return You can simply press RETURN and let BASIC determine memory size as long as you have a PR
57. ut how many characters you have deleted as you type underscores Here 15 a simple program you can key in and RUN 10 FOR I 1 TO 20 20 PRINT LOOP 30 NEXT I Loading a BASIC Program from Cassette Tape In 8K BASIC the CLOAD and CSAVE commands can be used to load and save programs from cassette The CSAVE command writes an image of the program as it exists in RAM to the tape Since the program in is already pre processed and encoded to run this format loads and saves more quickly than a printable listing of the program However this means the CLOAD command can not be used to load a program in printable ASCII format only programs previously saved with a CSAVE command Also since Extended BASIC encodes programs differently in memory than 8K BASIC files saved to cassette are not compatible between these two versions of BASIC The file BASIC BASIC Programs 8K BASIC cassetteDemo tap is an image of a cassette tape created by saving programs from 8K BASIC using the CSAVE com mand The tape contains two BASIC games hangman and lunar lander To load the hangman program type CLOAD H or To load the lunar lander program type CLOAD L After typing the desired load command and pressing return use the File gt Send File menu option in the cassette TeraTerm window to send the file cassetteDemo tap to the Altair BASIC scans the data coming in from the cassette looking for the one charac
58. will erase all floppy and PROM content and set all parameters to their defaults values Restore defaults y n 9 Update Firmware The Update Firmware menu option is used to install a firmware update into the Altair 8800 Clone Only perform this step if you have been instructed to perform the update See also the Cold Start Update Procedure Update Firmware This operation updates the Altair 8800 Clone firmware Do not perform this operation unless you have been instructed to perform the update Continue y n Cold Start Firmware Update If the Altair Clone is unresponsive the firmware can be restored without us ing the Configuration Monitor Terminal emulator settings for a cold start update are the same as for the Configuration Monitor 9600 baud 8N1 with power off raise and hold the left AUX switch in the up position then turn on power while continuing to hold AUX in the up position After about two se conds you will see the Update Firmware prompt shown above The AUX switch can then be released Follow the prompts to complete the software update pro cess f PART 3 TERMINAL EMULATOR A Overview A terminal emulator running PC is a convenient to duplicate the functionality of a teletype paper tape reader punch CRT terminal cassette interface capture printer output etc To provide these capabilities and other useful functions a terminal emulator with
59. y in ROM on power up or following a front panel reset The Turnkey Module also allows the 1K of ROM at 00 to OxFFFF to overlay RAM ROM is enabled at power up and on reset The ROM is disabled and RAM en abled upon execution of an IN instruction from OxFE or OxFF Since OxFF is the sense switch port booting from disk automatically enables all 64K of RAM because the boot loader PROM while executing from RAM does an IN operation from the sense switch port Note that the Altair Multi Boot Loader PROM MBL fails to run properly with the Turnkey Module installed since this PROM reads the sense switch port while executing from PROM effectively killing itself Turnkey Module Current setting Disabled 1 Enable Turnkey Module 2 Autostart Address FFOO Exit this Menu 10 4 Floppy Drive Type This option 15 used to select between the Altair 8 inch floppy the Altair Minidisk All three drives are affected After switching drive type be sure to upload disk images appropriate for the drive type selected Floppy Drive Type Current setting 8 Inch Floppy 1 8 Inch Floppy 2 Minidisk Floppy Exit this Menu 5 Floppy Performance The Altair Clone accurately duplicates the timing of the original Altair Floppy disk drive while authentic the slow speed can be frustrating after a while This menu allows choosing between maximum speed or real speed Actual speed is the default setting
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