I have source code and custom interface cards from ARP's project to create the first consumer computer controlled synth. The prototype was built out of an Altair 8800. Never finished, never released. It was a top secret project within the company I will try to scan the entire binder and recover all of the source code off of the 8" disks if it will help your project. Currently I think I am the only person who still has a copy of this information. I got it by accident when I bought ARP's Altair. ;) The binder has been sitting between the two front seats of my car since September. I'll have a good excuse to scan it on the 26th. ; ) This information has been left out of the history books! I'll include a few routines below... NOTE, I tried to recover the assembler written in "Altair Basic", but it is corrupted on the disk. The assembler program appears to have been written in Altair Basic with line numbers and then assembled by a special program. I would appreciate ANY information on this basic assembler! The person who wrote the routines below wrote a thesis at MIT in 1971 about the possibility of a computer-controlled synth. He was using a PDP-15 at the time. I can provide more information, but a good quote about the Altair 8800 Synth "One of my more impressive demos was doing four-part harmony using a woodwind ensemble (flute, oboe, clarinet and bassoon or French horn). Using the pro-soloists on the four-channel Bose system in the small lab sounded very grand. In fact, the lab was under tight security and not ever the VP of marketing was allowed in, though he tried. (We wanted them to sell what they had now, not get musicians waiting for things to come.) " Grant 0000 org 03fdh 0010 jmp presc 0100 org 0040h 0110 ************************************************************** 0120 * 0130 * Module PRESC 0140 * 0150 * Written by Bruce Cichowlas 8/25/76 0160 * Copyright Circle C - ARP Instruments 9/15/76 0170 * 0180 * PRESC - checks the preset panel and sets the previous 0190 * preset reading (prvpr), as well as the preset request 0200 * word (prerq). This routine should be invoked frequently, 0210 * as it actually does the preset panel scanning. 0220 * 0230 * No arguments 0240 * 0250 ************************************************************** 1000 presc equ $ 1010 push b 1020 lda ppadr ;preset panel addr 1030 ora a ;set flags 1040 jz pres1 ;none set 1050 mov b,a 1060 lda prvpr ;load previous reading 1070 ora b 1080 sta prvpr 1090 pres2 pop b 1100 ret 1110 pres1 lda prvpr ;find out if any were set previously 1120 ora a 1130 jz pres2 ;none before 1140 mov b,a 1150 lda prerq 1160 ora b ;include bits set in b 1170 sta prerq 1180 xra 1190 sta prvpr ;store 0 for the previous reading 1200 pop b 1210 ret 5000 ppadr equ 1800h 6000 *RAM 6001 prvpr equ 08ffh 6002 prerq equ 08feh 0000 org 03e8h 0001 jmp rdsld 0002 jmp clman 0003 jmp nmmsk 0004 jmp msknm 0005 jmp swpnl 0006 jmp clsw 0100 org 009bh 0110 ****************************************************************** 0120 * 0130 * Written by Bruce Cichowlas 9/3/76 0140 * Copyright Circle C - ARP Instruments 9/16/76 0150 * 0160 * CLSW - clears all switches. No arguments. 0170 * SWPNL - sets the switches from the scratchpad. Just 0190 * one byte of them for now. No arguments. 0200 * 0210 * MSKNM - Converts a one bit mask to a number from zero 0220 * to seven indicating bit position, e.g. 01h becomes 0, 0230 * 80h becomes seven. Input and output are from the A register. 0240 * 0250 * NMMSK - Performs the inverse operation of MSKNM. 0260 * 0270 * CLMAN - Clears the manual lights for the slidepots. No 0280 * arguments 0290 * 0300 * RDSLD - Reads a slidepot. On input, A contains 0310 * the slidepot number, and on return it contains the 0320 * slidepot's current value. 0330 * 0340 ******************************************************************** 1000 clsw equ $ 1010 sta swclr 1020 ret 1030 swpnl equ $ 1040 push h 1050 push d 1060 lhld prbas ;base of scratchpad 1070 lda slcnt ;slide count 1080 mov e,a 1090 mvi d,0 H 1100 dad d ;calculate address of switch values in the scratchpad 1110 mov a,m ;get word 1120 cma ;since switches use negative logic 1130 sta setsw ;set the switches 1140 pop d 1150 pop h 1160 ret 1170 msknm equ $ 1180 push b 1190 mvi b,7 1200 mskn1 rlc 1210 jc mskn2 1220 dcr b 1230 jnz mskn1 1240 mskn2 mov a,b 1250 pop b 1260 ret 1270 nmmsk equ $ 1280 push b 1290 mov b,a 1300 mvi a,1 1310 inr b 1320 nmms1 dcr b 1330 jz nmms2 1340 rlc 1350 jmp nmms1 1360 nmms2 pop b 1370 ret 1380 clman equ $ 1390 push b 1400 push d 1410 push h 1420 lda slcnt ;slide count 1430 dcr a ;convert to offset 1440 clma1 push m 1450 lhld lgbas ;man/auto light copy base 1460 call wrdbt ;get wrdbt offset 1470 xra a ;for reset 1480 call setwb ; adjust bit 1490 lxi h,lgdev ; light device 1500 mov e,b 1510 mvi d,0 1520 dad d 1530 mov m,a ;store new value 1540 pop m 1550 dcr a 1560 jp clma1 1570 pop h 1580 pop d 1590 pop b 1600 ret 1610 rdsld equ $ 1620 sta mxadr ;slidepot's MUX addr 1630 nop ;wait for MUX to settle 1640 nop 1650 sta strtc ;start conversion 1660 mvi a,6 1670 rdsl1 dcr a ;delay 1680 jnz rdsl1 1690 lda adout ;get a/d value 1700 ret 7000 *ROM parameter table 7001 prbas equ 0400h ;base of scratchpad 7002 slcnt equ 0402h ;slide pot count 7003 lgbas equ 0403h ;man/auto light copy base 8000 *Device addresses 8001 swclr equ 3003h ;store to this location clears the switch settings 8002 setsw equ 3004h ;store to this setting stores the complement of the 8003 * ;input into the switches 8004 mx88adr equ 3000h ;store to here sets the MUX slidepot address 8005 strtc equ 3002h ;store to here starts the conversion 8006 adout equ 3000h ;this is where the a/d output is put 8007 lgdev equ 3001h ;store to here sets the man/auto lights 9000 *Subroutine 9001 wrdbt equ 03e5h 9002 setwb equ 03e2h equ bins 6060 * 8000 swtch equ 01800h 9000 sortn equ 03f4h 9010 bncnt equ 03e