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A beast of a TI-99

E

epitaxial

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Joined
Mar 24, 2020
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This beast of a TI-99 was picked up at an estate sale. It belonged to a local TI-99 owners club and the old newsletters are all scanned if you google for West Penn 99ers. The Gram Kracker add on card seems like a very sought after peripheral. Buried inside the case is a hard drive and some RS232 add on card. I soldered together a video cable but get no output or signs of life. First I plan to remove the hard drive and do an image if its readable. Then check all the power supply voltages. Some pictures of the beast and crowded interior.

https://freeimage.host/a/ti-99.JY6OB
 
Crikey !

So its a TI99/4 in a custom case ? looks interesting.

The keyboard itself is worth a bit, want one for my XT but not paying ebay prices.
 
This thread was linked over on AA. https://atariage.com/forums/topic/311704-beast/

Have fun exploring that mystery treasure trove. Hope the hard drive is readable. Must be a controller for it to help id the format. The Pascal and Turbo mode are intriguing and what do the other switches do? Pascal might be another card hidden within. Might want to trace where the wires for those other front panel switches go.

Do you hear the drive spin up when you power it? If not, I'd be investigating the PS for signs of life before troubleshooting no video. Might be able to power the TI motherboard separately for early tests of it alone. You might not get much more than the title screen with no keyboard unless that's well-integrated to just the motherboard.

Lastly, I wonder if there's any sort of writeup on this uber-hacked 99 in their newsletter? Excellent legacy save, thanks for sharing and I wish you success in reviving it!
-Ed
 
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Based on the time it looks to have been built, the HD controller is probably a Myarc Hard and Floppy controller card. The hard disk side will control two MFM hard disks (most were either 20 or 40 MB BITD), and the floppy side will contol up to four 360K drives (some have an updated EPROM that ups that to 720K floppy drives). In the case of Pascal, that indicates there is a p-Code card in there (the switch turns it on and off, as it takes over the whole system when it boots). The turbo switch probably changes the clock speed between 3.58MHz and 4.0MHz.
 
Took some impressive ingenuity and thought to make that happen. Shame they didnt document and backup the whole process for the Other TI fans.
 
While I've accomplished zero projects of this magnitude, at the time I was modifying my TI or Timex, about the last thing on my mind was chronicling the steps for someone else who might care thirty years hence. Heck, I scarcely knew myself what I was gonna do next. Any pics of my mods, in the days of film, were taken long after the fact, at best.

I was too buried in sketches and books, and keeping the soldering iron from melting my multimeter or a power wire to worry about setting up the camera for a quick snap, lol! Now, I do still have all my handwritten notes or chicken scratches in book margins that guided me through it. But no pics and plenty of guesswork to decipher it all again today.

OTOH, this level of handiwork probably means some sort of documentation must have existed when it was being created at least. Hopefully it was preserved, but unfortunately the hardware and printed portions of estate collections get separated and nobody but the deceased knew the proper connections between the two to sort it out.
 
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