FarmerPotato

I appreciate learning anything about Exceltec. Unisource was a computer store in Lubbock, TX that flourished from 1983-1986. They sold TI-99/4A and C-64 and others. I first saw Micropendium there. I never had the mail order catalog because I rode my bike over there. It was the place to go to see exciting stuff like SuperSketch and the MBX. Sunware had an office a short distance away, in Pyramid Plaza Office Building. The pyramid itself was a sight. The TI West building was also nearby. I first saw the Sunware name placard while going upstairs to a restaurant that had an Omega Race video game (my kid brain was wired like a squirrel to recall all the arcade game locations). The rumor was that some of the best TI game programmers were working at Sunware after TI. It was a mysterious place. I played a Sunware Space Patrol cartridge at a friend's house (when it was still Sunware.) I think it came from the Unisource store. I wanted to publish Bubble Plane as a cartridge, and got an informal meeting with a Sunware employee. I was trying out an Extended Basic compiler and didn't know if that would ever work out to make a game into a cartridge (no). I was told to come back when I had an all assembly language game. I also saw the Love Tennis game (I didn't admit I'd already seen a leaked copy.) Years later I really finished my game, using the Geneve to emulate bank switching for 32k cartridge (8k game + 24k graphics and level data). I didn't know how to get it published. Unisource was in the news after a burglary in 1985. At the same time, multiple Corcomp 9900 MPES + dual floppy were offered for sale on a local bulletin board, cheap, $200 with printer. I persuaded my brother to buy one. My TI-Net BBS was developed on one MPES, and run on another one. I have a strong suspicion that the MPES was fenced. The seller, we'll call him Frank, was briefly enthusiastic about using the TI-99/4A and getting software to other new users. Then Frank abruptly left town, still owing my brother $60 for selling the printer to someone else. -Erik

Challenge: Write a description of an original TI-99/4A game that you would mashup with another game. The mashup game will use characters and game play from BOTH games. Example: Cars and Carcasses and Katamari In this update of a 1982 Not-Polyoptics game, you are trapped in a car in a graveyard full of zombies, vampires, and Frankenstein's monsters. You must run them over, while not crashing into any tombstones, until your car grows into a sticky ball of monster carcasses, capable of rolling over everything in its path. Clarification: You don't have to write the game, only imagine it! Prizes: We all win.

Here is a related anomaly in TI-99/4 BASIC 10 CALL CLEAR PRINT CHR$(7) EDIT 10 10 The bug was documented as using a "statement used as a command" then editing a line. TI inserted an ERRATA sheet into the 99/4 packing, practically daring you to try it. The effect was that the entire contents of VDP RAM was shifted down by 1 byte. I can understand this in terms of TI BASIC compacting the program in VDP RAM, moving everything up 1 byte, counting down the addresses, but the start address is corrupt and the process goes on and on. First there is a delay. Then you observe the pattern table shifting down 1 pixel row. All the visible chars drop one pixel lower, but not all at the same time. It's slow enough for you to have a thought that your program is gone and memory is being trashed. Then the screen fills with sprites and gibberish, and the really bad stuff begins. Yes, decrementing the VDP address below 0 means it is time to write random values into the VDP registers! LI R0,>FFFF SWPB R0 MOVB R0,@>8C02 SWPB R0 MOVB R0,@>8C02 DEC R0 JMP $-14 Yikes! On a TV output, this means the screen begins to "tear". There are seconds of darkness, then a flash of bright white, followed by pulses of distorted video between which fragments of your program are briefly visible. There is an audible whine from the television set as the video signal pushes it beyond its comfort envelope. In my 8 year old mind this was what FUBAR meant. However, after a time, the madness ceases. The blackness is still. There is a softly blinking spot. The cursor is back! You press enter; nothing improves. You make a syntax error, and the screen is somewhat restored. If you are lucky, there are sprites, which you can play with by typing under them. Just don't type LIST, or the horror may begin all over again. The cursed number 32767 may appear. I still feel a fricasee of dread when I cross its path.

The older chips accepted a clock frequency of 447 KHz: TMS9919 SN94624 SN76494 These all have an internal clock divider of 2. The TI-99/4A had an external 74LS161 to divide the VDP clock 3.579 MHz by 8. For external sales (saving a part cost), TI incorporated the divider into the chip in these parts: SN76489 uses 3.579545 MHz internally dividing by 16. SN76489A SN76496 differs in that it also has an AUDIO IN If you put an SN76489A in an older console, it would technically be out of spec, but if it worked at all you would get much lower frequencies (extra divide by . I'm double checking all these details again tomorrow, as I've received a batch of SN76489A from China for FORTI card builds and I'm going to leave out the external divider.

Thank you for the comments. I am continuing to work on this. I will have a source code update next weekend. In the absence of a copy of the actual FORTI distribution disk (D), here is my plan: Road Map for FORTI Clean source (compilable) for (B) Bach Demo and © Chariots of Fire, Ricercar a 8. Including some defining word features implemented to match (D) FORTH assembler version of MUSIC, as well as CODE version (machine code) Full implementation of features of (D) from user manual, with some innovations. Collection of Bach inventions and sinfonias for 2-3 voices MIDI import tool TRON arcade game music (originally used AY-8910) Well-known TI game songs remixed Tool to export compiled music as A/L source for use outside FORTH Reference release (E) (Erik) with innovations 4-chip FORTI card PCB (not made yet) Extra special music card project compatible with FORTI (hardware built! waiting while I do software) Major musical work demo MIDI player Speech synthesizer integration Animatronic art installation

Since Extended Basic just sets error to 130 meaning I/O ERROR, I think you have to retrieve the error byte from the PAB in VDP. I've never done this from Basic, but here is a beginning: Theory This would apply if the file were still open (no help with a DELETE statement!) Start with the PAB list. Get the 2 bytes at CPU address >833C (Somebody shoot me if I'm wrong. I'm just reading the docs for the first time since Craig Miller covered XB VDP memory in detail in Smart Programmer.) http://www.unige.ch/medecine/nouspikel/ti99/vdpram.htm That gives you a VDP address to start looking at. The VDP memory contains a linked list: 2 bytes: next PAB's VDP address or 0 1 byte: file number 1 byte: hmm 10 bytes: PAB with length byte at byte 9 N bytes: filename If the IO error was for a file # that is still open, there would be a PAB entry for it. Assuming you had CALL PEEKV.. (probably you get your own and write CALL LINK("PEEKV", A,B,C,D ) etc CALL PEEK(-31940, A, B) V = A*256+B CALL PEEKV(V, A, B) V2 = A*256+B CALL PEEKV(V+2, FILENUM) Inside the PAB structure, byte 0 is the operaton and byte 1 contains the error code (upper 3 bits). http://www.unige.ch/medecine/nouspikel/ti99/headers.htm#PAB CALL PEEKV(V+4, A, B) E = A*10+INT(B/32) E would be your I/O Error code. I don't think there's anything in that table for a DELETE statement that doesn't keep an open file, so no juice. But I think this is the answer for a file that is still open. TEST So I tried this 10 ON ERROR 50 20 DELETE "DSK2.HHHH" 30 END 50 CALL ERR(A,B) 60 PRINT A,B 70 GOTO 70 Without the ON ERROR I get I/O ERROR 73. Poking around at runtime, I find a likely PAB at VDP >37A9. It starts with 07 60 which is the opcode DELETE and error bits 011 or 3. The length byte is at >37B2 Size of PAB is 10 + 9 for the filename which makes the next VDP address >37BC I looked for anything in CPU RAM pointing to those addresses. Nope. I guess though that this is inside the String Space.. Basic made a temporary string allocation and then freed it? I'm not sure. Now I want to know the answers!

Here is a photo of mine. It shows 4x 2564s with date code 8327 for 32k and 2x 6116 RAMs for 4k .

It has not powered up. I do not see full voltage on the power brick, with no load, so that may be the issue (it is just a linear transformer in there?) I don't have a bench power supply. I purchased a LCR meter so I'm going to start checking components. Starting with the big capacitor.

Hello, I'll be visiting Portland from May 25-30. If there happened to be a TI meetup, I will do my best to bring my projects to demo.

Hi 99/2 owners, I've been following this thread eagerly. I have a 99/2, though it stopped working some years ago. It looks to have 32K ROM after piggy-backing a 2564 (28 pin) with some Kynar wiring. I have a plan to dump the ROMS in-circuit if I can't power it up.

I ordered two! Any chance of offering a kit form? I would order two more for the future.

This is a pretty simple chip. PAL12L6 : 12 inputs, 6 outputs http://pdf1.alldatasheet.com/datasheet-pdf/view/126104/ETC1/PAL12L6CN.html There is no feedback. (no flip-flop, register, memory etc.) So a simple scan of the 4K input combinations will reveal all the outputs. Reduce and recover the equations.

Download the binaries here: Bach Demo for "Little" Fugue in G Minor 6 LOAD BPLAY Chariots of Fire for Chariots of Fire: 59 BLOAD PLAY or for Ricercar a 6 49 BLOAD PLAY

May 4th Musical offering: FORTI Decompiled 1. Introduction FORTI was a sound card for the TI-99/4A PEB, with software written in FORTH. It featured 4 of the TI sound chips, giving 12 programmable voices. Each chip's tone#3 generator was paired with a noise generator, for bass or percussion. The FORTI software was best known in the form of its 3-voice demo of Bach's FWV 578 "Little" Fugue in G Minor (G-Moll), distributed with the TI FORTH Demo disk in 1983-84. The Bach demo used only 3 voices, on the sound chip in the 4A. However, other compositions were made for 12 voices. I know of Chariots of Fire (Vangelis), Ricercar a 6 (Bach, Musical Offering, aka Prussian Fugue), and a newer Bach "Litle" Fugue (first 1K lost). On the plain 4A, these sound terrible but tantalizing, as 11 voices compete skilfully but hopelessly for 3 hardware sound channels. What I did Starting from a compiled FORTI demo of Chariots of Fire, I decompiled the FORTH words, read out data structures, and disassembled the code for the MUSIC word, which is in the ISR sound driver. I benefitted from a small amount of leftover original source (from the corrupted Bach demo) and the FORTI user manual, but most of FORTI, especially the music compiling words, is lost to me and has to be reverse engineered. From internal evidence, the Bach demo is older than Chariots of Fire. The FORTI user manual indicates features not supported in the Chariots of Fire MUSIC driver, which I may create again. I classify features into three versions of the FORTI software: B. Bach Demo (TI FORTH graphics demo) C. Chariots of Fire D. Distribution with FORTI manual Unless stated otherwise, I discuss features found in Chariots of Fire. 2. Capabilities of FORTI: 2.1 The Data Structures Voiceline - a list of note numbers (byte) and duration in ticks (byte). Envelope - a list of attenuation bytes, with looping index (high bit set). Workspace - set of 16 TMS9900 workspace registers holding the context for one sound channel. Pitchtable - arrays of frequency cmds for each note number. 2.2 The capabilities of the MUSIC ISR routine For each of 12 voices, there is a separate voiceline, envelope, and pitchtable, assigned to a hardware sound channel. The differential tempo counter: Note durations in ticks (1/60th second) are multiplied by 32 and added into a "Next Note" countdown timer (per voice). On each interrupt tick (1/60th second), the value DEL is subtracted from the countdown timer. DEL has an initial value of 32. When DEL is modified by the RIT, ACC, and TEMPO words, the effect is that the tempo is increased or decreased. The duration timer is never cleared so no time is lost. All voices move ahead at the same tempo. When the duration timer reaches 0 or less (it is initialized to 0 to start music) a new note and duration are taken from the voiceline. If the duration is 0, the channel is silenced, and the ISR returns -1 on the stack (bug: and the ISR is removed?) Looping inside the envelope: in terms of an ADSR model, the envelope will begin with an Attack-Decay section, a Sustain (looped) section, and an optional Release (tail) section which can apply during the last portion of each note. The Release feature is used in the Bach Demo but not Chariots of Fire (buggy). Envelope bytes are processed every tick (1/60th second), not modified by tempo. The 16 attenuation values are remapped through a dynamic offset DYN and a 48-byte dynamics table (DYT). This allows words like +VOLUME and -VOLUME to take effect 2.3 Pitchtables A pitchtable entry is 2 data bytes to send to the sound chip for a note number (the channel number will be added later). Note number 0 is used as a rest, but a rest is actually defined by having 0 for the sound chip period. PT0 is the regular pitchtable. Note number 37 corresponds to low A or 110 Hz, which is the lowest musical note a tone generator can produce. Because of this limitation, PT0 fills the bottom 3 octaves (notes 1-36) with a copy of the octave 37-48. If a voice using PT0 plays notes in the range 1-36, they will still be heard, but in a higher octave. PT1 notes load white noise for percussion. PT4 is for channel 3 to drive the periodic noise channel and begins with note 0 corresponding to 13.75 Hz. 3. Examples: Voiceline: 0 VARIABLE VOICE1 QU C D E F EI G A B C 0 , compiles a list of note-duration pairs into VOICE1 relying on definitions such as these: 49 VARIABLE XPOSE : &* XPOSE @ + SWPB DURATION [email protected] + , ; : A 0 &* ; : A# 1 &* ; : C 3 &* ; : AA 12 &* ; : CC 15 &* ; : EI 24 DURATION C! ; : QU 48 DURATION C! ; : RE DURATION [email protected] , ; : OCTAVE 12 * 49 + XPOSE ! ; ( n -- ) The FORTI manual says to compile a voiceline like so: START VOICE: VOICE1 ( 1 ) QU C D E F ( 2 ) QU G A B C FINIS My example based on C/ uses a lower level way: ( Verdi Requiem Mv2 trumpet ) 0 OCTAVE 0 VARIABLE VOICE2 ( 131 ) 3E RE C E G E G RE C E G E G ( 132 ) Q CC RE RE 3E C E$ A$ ( 133 ) Q CC H RE 3E C E$ G ( 134 ) Q C RE H RE 0 , 4. Internals 4.1 Workspace registers FORTI takes advantage of the TMS9900 workspace pointer context. There is a block of 12 workspaces allocated in the dictionary, one for each voice. In MUSIC version C with dancing sprites, they must be contiguous so that a sprite table address can be found from (STWP-WS1)/8. In version B they are not contiguous. In the Bach demo, (no sprites) Workspace WS1 might be set up like this: VOICE2 VARIABLE WS1 PT0 , TRUMPET1 , 0 , 0 , 8000 , 9000 , 12 ALLOT But with dancing sprites, all WS must be contiguous, in order to calculate the sprite#. 0 VARIABLE WS1 17E ALLOT WS1 20 + WS2 CONSTANT WS1 40 + WS3 CONSTANT WS1 60 + WS4 CONSTANT WS1 80 + WS5 CONSTANT WS1 A0 + WS6 CONSTANT WS1 C0 + WS7 CONSTANT WS1 E0 + WS8 CONSTANT WS1 100 + WS9 CONSTANT WS1 120 + WSA CONSTANT WS1 140 + WSB CONSTANT WS1 160 + WSC CONSTANT The word MUSIC is the core of the ISR and is written in assembler. The first instructions of MUSIC pulls the WP off the stack; ED10 0201 LI R1,>ED18 ED12 ED18 ED14 C019 MOV *SP,R0 fetch WSP ( wsp -- f ) ED16 0400 BLWP R0 effect is R0->WP R1->PC. no LWP on 9900 The full code is in Listing 1 at the end of this article. The workspace registers are initialized before MUSIC first runs, and have the following meaning: FORTI WS usage. WS is a register workspace ------------------------ R0 voice or cascade addr. List of byte pairs (note#,dur) R1 pitch-table: e.g. PT0 or PT1 R2 envelope. e.g. PLUCK3 or ORGAN2 R3 index into envelope R4 countdown timer to next note. init to 0 to begin. R5 const pitch cmd byte R6 const attn cmd byte (for a noise, pitch is tone#3 and attn is tone#4/noise) R7 pitch cmd word for current note or 0 for rest R8 temp. compute vdp address (for sprite) or envelope address R9 vdp addr of sppat# R10 copy of SGCA, sound card address (copied from SGCA at each ISR entry, sic) R11 not used R12 temp. compute vdp data byte (for sprite) R13 ... R15 after blwp, not used ( Register numbers for use in assembling MUSIC - EO ) 0 CONSTANT NTP ( Note table / voice pointer ) 1 CONSTANT PTS ( pitch table start ) 2 CONSTANT ATS ( attenuation table start / envelope ) 3 CONSTANT ATP ( attenuation table offset ) 4 CONSTANT DUR ( countdown timer duration ) 5 CONSTANT PVID ( pitch voice ID ) 6 CONSTANT VVID ( volume voice ID ) A CONSTANT SG ( sound card address ) C CONSTANT PNDX ( pattern number vdp address ) ( D E F are clobbered on entry to MUSIC but could be temps ) 4.2 Player wordsWords PLA1, PLA3, PLA12 begin playing 1, 3, or 12 voices, resp. : PLA12 ' BMUSIC XMUS ; ( play : PLA3 ' CMUSIC XMUS ; ( play only WS1-3 on internal snd only ) : PLA1 ' DMUSIC XMUS ; ( play only WS1 on internal snd only ) where : MUSIC0 85EE SGCA ! MUSIC ; ( 1110 1110 only chip #0 with enable low ) : MUSIC1 85F6 SGCA ! MUSIC ; ( 1111 0110 only chip #1 ) : MUSIC2 85FA SGCA ! MUSIC ; ( 1111 1010 only chip #2 ) : MUSIC3 85FC SGCA ! MUSIC ; ( 1111 1100 only chip #3 ) : MUSIC4 84FE SGCA ! MUSIC ; ( 1111 1110 internal only ) : MUSIC5 857E SGCA ! MUSIC ; ( 0111 1110 say chip 4 ) : MUSIC6 85BE SGCA ! MUSIC ; ( 1011 1110 say chip 5 ) : MUSIC7 85DE SGCA ! MUSIC ; ( 1101 1110 say chip 6 ) 3424 VARIABLE PSTART : XMUSIC WS1 MUSIC0 OR IF 83C4 @ PSTART ! 0 83C4 ! OFF ENDIF ; : DMUSIC 0 XMUSIC ; : YMUSIC WS2 MUSIC0 WS3 MUSIC0 OR OR XMUSIC ; : BMUSIC WS4 MUSIC1 WS5 MUSIC1 WS6 MUSIC1 WS7 MUSIC2 WS8 MUSIC2 WSA MUSIC3 WSB MUSIC3 WSC MUSIC3 OR OR OR OR OR OR OR YMUSIC ; : CMUSIC 0 YMUSIC ; ( for PLA3 ) : XMUS CFA ISR ! INTLNK @ PSTART ! ; When playing just one voice: : MUSIC0 85EE SGCA ! MUSIC ; ( 1110 1110 only chip #1 with enable low ) : XMUSIC WS1 MUSIC0 OR IF 83C4 @ PSTART ! 0 83C4 ! OFF ENDIF ; ( f/finished? -- ) : DMUSIC 0 XMUSIC ; : PLA1 ' DMUSIC XMUS ; ( play only WS1 on chip#1 or internal snd ) In PLA1, DMUSIC is the ISR which calls MUSIC on one workspace pointer. (PLA12 and BMUSIC make a player that calls each of 12 voices.) 4.3 Sprites The version of MUSIC in Chariots of Fire draws dancing sprites on the screen (Bach demo does not have this.) For each of 12 voices, there is a sprite. The note number translates to a column on the screen, while the attenuation is shown by a colored bar where height indicates loudness. 4.4 Misc Chariots of Fire utilizes 11 sound channels across 4 chips. Interestingly, it defines addresses for MUSIC5,6,7 as if the author imagined having more chips than 4. 5. Optimizations It's quite likely that I'm not analyzing the final version of the MUSIC word. That said, I see the following optimizations that could be made: * SGCA is placed on the stack and copied to the workspace R10 on each tick. This should be configured before music starts playing, just like other registers that don't change. * The envelope release (or tail) segment looks buggy in Chariots of Fire (whose envelopes don't rely on it.) * Byte swapping and SRL by 8. movb *r8,r8 ab @DYN+1,r8 srl r8,8 movb @DYT(r8),r8 movb r8,*r10 could be clr r11 movb *r8,r11 swpb r11 a @DYN,r11 movb @DYT(r11),*r10 6. Missing Words Parts of the music entry system were not present in the compiled demo: Defining words like VOICE: FINIS and <ENV: ENV> were not recovered. I speculate that the demos B and C were created in a lower level way, and that these defining words were invented for the final distributon. Envelope word =REPEAT to encode the sustain loop 3 SHARPS established a key signature, modifying the behavior of note words like F. In the demo, F pushes a constant note number 8 (plus octave). This implies T for Tie or slur is not present. I don't see that MUSIC implements any means to vary frequency. R: and :R to repeat a section in a voiceline. These save memory, but would require runtime implementation in MUSIC. convenience word =TEMPO counting words =MEAS and +MEAS Envelope defining words <ENV: ENV> produce code that copies the envelope PFA into a WS. This requires a <BUILDS DOES> construct. In the demo, envelope words are just arrays. The words +VOLUME and -VOLUME and dynamic markings from PPP to FFF. CONDUCTOR is the top defining word and is not present SILENT is not present +FIFTH and words that transpose voices at runtime, not compile time, will require support in MUSIC. <ALBUM and ALBUM> words =GR and GR that subtracts time (for a grace note) from the previous note duration. In the demo, GR sets DURATION to 1 tick. =FERMATA and FERMATA =DRUM to set a WS to play noise <PHRASE: PHRASE> 7. Future Innovations I was disappointed to find nothing about tremolo in this demo. Envelopes are just attenuation changes, which is how an organ tremolo operates, but on other instruments, tremolo means to vary the frequency, or play two frequencies for the overtones. (T or Tie/Slur effect on frequency is unknown; perhaps it just skips the tail.) An envelope for pitch would allow many more effects. The FORTI manual lacks a dictionary. The pitch table is flexible enough to allow different temperament. The pitch table we take for granted is the equal tempered system in which music can be transposed to another key without changing its character. 8. Acknowledgments David Olson retrieved the Chariots of Fire demo disk. Rene LeBlanc for his FORTH disassembler, which I obtained in 1985 and never used until now. Gene Hitz and Owen Brand provided the MATIUG disk library, which I converted to DSK format, finding the TI FORTH source. The BERG/WERNECKE FORTH decompiler found in the MATIUG disk library. Lee Stewart's fbFORTH and TI FORTH manuals which I used as a reference throughout, especially on the dictionary entry structure. Tursi for Classic99 in which I did most of the work. Kryoflux hardware and software was used to efficiently acquire hundreds of legacy disks. CANTRELL, the TI engineer named on the FORTI "stereo card" schematic. Who is CANTRELL? 9. References FORTI Music Card Users Manual and Schematic at WHTech ADSR definition Listing 1 * code field of MUSIC * Load workspace from stack arg ED10 0201 LI R1,>ED18 ED12 ED18 ED14 C019 mov *SP,R0 fetch WSP ( wsp -- f ) ED16 0400 blwp R0 effect is R0->WP R1->PC. no LWP on 9900 ED18 C2A0 mov @SGCA,R10 ECCE is pfa of variable SGCA. typ 85EE(#1 chip) ECCE ED1C 04CC clr R12 ED1E C104 mov R4,R4 duration timer. clear to start ED20 1531 jgt LABEL2 * next note ED22 D330 movb *R0+,R12 get note number in R12 ED24 098C srl R12,8 ED26 C1CC mov R12,R7 get note number in R7 ED28 0A9C sla R12,9 sprite col = note# * 2 ED2A 0209 li R9,>d844 WS1 D844 ED2E 02A8 stwp R8 ED30 6209 s R9,R8 (WSx - WS1) is a multiple of 32 ED32 0938 srl R8,3 divide by 8 ED34 0228 ai R8,>4301 address to write, in SAT 4301 ED38 06C8 swpb R8 ED3A D808 movb R8,@>8c02 set up VDP address 8C02 ED3E 06C8 swpb R8 ED40 D808 movb R8,@>8c02 8C02 ED44 D80C movb R12,@>8c00 sprite col = note# * 2 8C00 ED48 0588 inc R8 ED4A C248 mov R8,R9 vdp addr of sppat# ED4C D230 movb *R0+,R8 duration ED4E 0988 srl R8,8 ED50 0A58 sla R8,5 times 32 . 32 is the neutral value of DEL ED52 A108 a R8,R4 add, because need to pay time debt ED54 1509 jgt LABEL1 * silence * bug: if R4 is at worst 1-DEL, R8 is at worst 32, if R8<DEL-1 then music may stall FINIS ED56 0640 dect R0 leave R0 pointing to the last (valid) note ED58 C206 mov R6,R8 attn cmd byte ED5A 0228 ai R8,>0f00 silence 0F00 ED5E D688 movb R8,*R10 write to sound chip ED60 02E0 lwpi >8300 8300 ED64 0719 seto *SP put -1 on the stack ( wsp -- f ) ED66 045F b *NEXT LABEL1 ED68 A1C7 a R7,R7 note# * 2 ED6A A1C1 a R1,R7 pitch table address ED6C C1D7 mov *R7,R7 ED6E 1605 jne NOTE else, turn off voice: REST ED70 C206 mov R6,R8 attn cmd byte ED72 0228 ai R8,>0f00 silence 0F00 ED76 D688 movb R8,*R10 write to sound chip ED78 1005 jmp LABEL2 why not LABEL6 NOTE ED7A A1C5 a R5,R7 pitch cmd byte ED7C D687 movb R7,*R10 write to sound chip ED7E 06C7 swpb R7 ED80 D687 movb R7,*R10 write to sound chip ED82 04C3 clr R3 * note in progress LABEL2 ED84 C1C7 mov R7,R7 pitch cmd or 0 if none ED86 132E jeq LABEL6 nothing to do ED88 D212 movb *R2,R8 envelope first byte (N in sustain) ED8A 0938 srl R8,3 ED8C 8108 c R8,R4 R4 is counting down from duration*32 ED8E 1501 jgt SSTAIN ED90 1003 jmp LABEL3 SSTAIN ED92 0203 li R3,>003f start envelope at 3fh-R8*32 003F ED96 60C8 s R8,R3 LABEL3 ED98 0283 ci R3,>003f 003F ED9C 1102 jlt LABEL4 ED9E 0203 li R3,>003f R3 max 3F 003F LABEL4 EDA2 0583 inc R3 at least 1 EDA4 C203 mov R3,R8 EDA6 A202 a R2,R8 envelope pointer in R8 EDA8 D218 movb *R8,R8 EDAA 0988 srl R8,8 EDAC 0288 ci R8,>0080 0-F attentuation, 8x cmd byte 0080 EDB0 1501 jgt ENVJMP EDB2 1006 jmp LABEL5 * envelope cmd byte ENVJMP EDB4 0228 ai R8,->80 FF80 EDB8 C0C8 mov R8,R3 new envelope index in R3 EDBA A202 a R2,R8 EDBC D218 movb *R8,R8 they seem to have run out of registers EDBE 1001 jmp LABEL6 * R8 lsb is attn LABEL5 EDC0 06C8 swpb R8 * adjust attn by dynamics table LABEL6 EDC2 B220 ab @DYN+1,R8 ECD9 EDC6 0988 srl R8,8 ugh EDC8 D228 movb @DYT(R8),R8 D1BA EDCC 06C9 swpb R9 vdp address of sppat# EDCE D809 movb R9,@>8c02 8C02 EDD2 06C9 swpb R9 EDD4 D809 movb R9,@>8c02 8C02 EDD8 0A28 sla R8,2 mpy by 4 EDDA D808 movb R8,@>8c00 set sppat# to attn 8C00 EDDE 0928 srl R8,2 EDE0 A206 a R6,R8 add attn cmd byte EDE2 D688 movb R8,*R10 write to sound chip LABEL6 EDE4 6120 s @DEL,R4 Subtract DEL from timer CC60 EDE8 02E0 lwpi >8300 8300 EDEC 04D9 clr *SP put 0 on the stack EDEE 045F b *NEXT

I heartily agree. I celebrated by beginning the day in TI FORTH and downloading Starting FORTH to my phone again. That said, I also got out LEGO Yoda #7194 and I hear there are Wookie Cookies nearby.

I might be able to go to the SMU library in Dallas. Thank you for pointing this out! What sections do you think are most relevant? I think RG-14 Consumer Products Division.

I can work with that.. There is already a STWP which I can keep around in R13. STWP R13 this is already paid for CLR R11 MOVB *R8,23(R13) to low byte of R11 Based on Rasmus' cycle counts, this is at best slightly faster. (Note: registers are in external ram >D844) I see this code 2 times, so I consider AI R13,23 point to R11 lsb Then each time MOVB *R8,*R13 I can take care that the high byte of R11 will stay 0.

Thanks - I've been watching eBay for these for a month or so - this one is mine now. I put my first 910MP (from PC Liquidators) in long-term storage for Midwest Gaming Classic. We used it on the 4A and Geneve (composite only). Long-term storage means I only get it out when the show is held. I am NOT traveling with that thing again. (I took a full P-Box, disassembled 910MP, Geneve with keyboard, plus my main F18A console on the plane. All but the F18A console and Geneve card went into long term storage.)

I have been finding this in ISR code and I am wondering how wasteful it is in cycles? Would someone who knows TMS9900 timing care to analyze it? All registers are in external RAM (full wait state penalties). movb *r8,r8 srl r8,8 Proposed Optimization: clr r11 movb *r8,r11 swpb r11 The programmer has RUN OUT of temp registers and is overusing R8, but I see R11 is free. Thanks in advance!

Love it! I look forward to ordering a lifetime supply from you!