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I received and email the other day from a TIer who is getting back to his machine after a 20-year hiatus (sounds familiar.) He had an interesting story and said I could share it on the forum. I'm trying to get him involved over here on the forum, so maybe this will help... ;-) He created an account (TI Treker, a handle he said he used on BBSes back in the day), so look for him. Anyway, here is the story:




I did accomplish this idea once before when I was 22 yrs. old. It was written in TI-Forth and worked really well. My apartment got broken into and the theif took all my computer items (and audio equipment, etc, etc), and IBM had just come out so I changed over to the IBM format and finished the project using the equipment for that machine.


My TI-99/4A had a digitizer card in it. The individual who made the card died shortly after he finished it and he only sold 5 of them and so, that was another reason for the change over.


I started to resurrect the project, now that I am (Matthew edit: age removed), since it was an unfinished job. I was able to collect all the equipment, except the exact A/D converter card I had used which had some really good extra features and a very well written DSR.


A fellow TIer (Bob) had a defective A/D-Clock card he sold me and I was able to get the card working. It lacks the parallel output port that the old card had, but I can program around that issue to the PIO in the expansion box. Bob really saved the project for me by having an old A/D card.


I can not believe I have forgotten so much of the Forth Language after so many years. I know the old disks with the original programs are probably some where, but where is the question. So I started all over again.


I do know, even back then, I was able to get 4K samples a second from the TI-99/4A using TI-Forth. Not much time when using less than 24k of memory, but it would even do music, and at 8-bits resolution at that. I was able to load the last 8 bytes with data and then use the first 7 bytes in memory since the locations are in pairs in a second pass of the digitizer, but I just had to keep the digitized data limited to 7 bits on the last pass, which was easy to do. It did not seem to matter much in the sound playback quality. The volume was sufficient, to say the least, just on 7-bits. I used every bit of spare RAM in the machine, even in the video RAM section for temp. data storage.


I then burned the data from the machine using my home made EPROM programmer and was able to export the digitized sound to a portable playback unit and store the data to a diskette.


Well, that's the story and why my project ended with the TI-99/4A. Took some theif who liked to trash peoples lives and equipment to end a worthy project. TI at that time had just announced that it was no longer going to support the machine, the Austin Texas TI Users group was disbanding as well because of the lack of support, so those are other reasons I went to the IBM machine. The police never caught the guy either who broke into my place.


I think if IBM had had the GROM system, which automatically incremented the address by one each time the ROM was read, we would have had far better machines today and faster ones.


It's too bad TI was so greedy with their technology back then, but if you lived in Texas back then, you would know that was the mind set of corporations, it is just that TI had a far worse case of it than most.

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