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Was there more than 1 variation of the TI-99/4?

ti-99/4 variants

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#1 majestyx OFFLINE  



  • 276 posts
  • Location:Port Carbon, Pennsylvania

Posted Sun Dec 30, 2018 4:12 PM

I could swear I had read a discussion here some time ago about there being two versions of the first TI Home Computer, the TI-99/4 but can't seem to find it anywhere. I am asking because I've recently gotten a hold of one of these, but am waiting on a cable to arrive in order to hook it up to a modern display in order to find out if it even still works. I'm just curious to know what was different between the two if indeed there were two versions of it. Unfortunately the one in my possession had the serial number scratched off of it so it may be impossible to determine which one I have. I think it would be based on the serial number matching up to the production run. Regardless, if someone could confirm or deny that there were two different 4's, I'd greatly appreciate it.

#2 blackbox OFFLINE  


    Chopper Commander

  • 239 posts
  • Location:England

Posted Sun Dec 30, 2018 4:31 PM

I have used two different TI99/4 consoles. First up was an NTSC console which had to be plugged into an American NTSC monitor. This used a fairly standard analogue RBG output (later fed to a tv modulator). The US version had sound on the tv set.

Then came the PAL model, which used a different graphics chip and a very different- nearly unique- video output. The UK model ran slightly slower than the US model (50 fps instead of 60fps) which caused problems for Extended Basic programs where game play was thrown by a differing sprite speed. UK owners had to use the tv modulator to watch on a 625 line German tv set in colour (bizarre- TI produced the tv modulators for the European PAL standard, which differed from the UK PAL enough to make tuning properly with a UK TV a headache!). You could watch in monochrome on a monitor, but finding a colour monitor that could handle the very unusual signal was nearly impossibe (only the Tatung monitor could take the signal). The PAL 99/4 had a small speaker behind the console grill and a slider volume control at the front of the module depression (the US model had a nameplate here).

Edited by blackbox, Sun Dec 30, 2018 4:48 PM.

#3 Ksarul OFFLINE  



  • 5,319 posts

Posted Sun Dec 30, 2018 5:57 PM

I have two of the 99/4 consoles with the sliders. I can only say one very important thing about them: do not ever use a regular power supply with them, as doing so WILL destroy the machine. All of the AC to DC conversion for this type was done in the external power supply, as the board for the sound slider occupies the space where the internal AC to DC power supply would normally have been. Both of mine are also NTSC machines. They were all produced during a very short period at the end of 1979 and the beginning of 1980 (I personally haven't seen any with production dates much beyond the end of January, but that doesn't mean there aren't any). The slider also shows the original purpose for the slot that has the Solid State Software badge in it. One other note: the correct power supplies for these are harder to find than the consoles are--and the power supplies are usually in dire need of recapping when you do find one. . .

#4 majestyx OFFLINE  



  • Topic Starter
  • 276 posts
  • Location:Port Carbon, Pennsylvania

Posted Sun Dec 30, 2018 6:44 PM

Thanks for the information! I should have mentioned this is a U.S. machine.


I knew there was some difference and it is the volume slider. Mine has the"Solid State Software" badge on it so it's definitely not the short run version. Not sure if it's the original power supply. It's a model AC95000 with the plug on a large cube transformer. It's been so long since I used a TI. I gave away both of my 4As along with a loaded PEB, speech synthesizer, joysticks, tape drive, plus tons of add-ons, software and documentation/magazines back in 2010 and wish I had them back!

#5 Ksarul OFFLINE  



  • 5,319 posts

Posted Sun Dec 30, 2018 7:01 PM

As long as yours outputs the standard AC voltages and you have the internal DC power supply board, that should work fine. . .

#6 globeron OFFLINE  



  • 850 posts

Posted Sun Dec 30, 2018 9:52 PM

Let me know if I need to check something on the TI-99/4 (currently mine are stored in cardboard

boxes in Bangkok, but I can access them easily, before flying back to The Netherlands over 3 days).




I have 2x different TI-99/4 and they have different power supplies:

* 1x with normal pins power adapter

* 1x with the "big pin" power adapter (which broke and I replaced it with a special meanwell adapter, see PDF for details)


Pictures - Side by side comparison:

Part 1* http://atariage.com/...here/?p=4021546

Part 2* http://atariage.com/...here/?p=4021547

Part 3* http://atariage.com/...here/?p=4021550



1. Replacing the "big pin", with great help of Ksarul to understand the differences. Hereby is an article

(written in Dutch and also published in the TIjdingen). Use translate.google.com to convert to English:

Attached File  TI-99-4-Speciale-Voedings-Adapter.pdf   442.38KB   3 downloads


Facebook: https://www.facebook.com/groups/2209774843/permalink/10155938783199844/



Attached File  IMG_20171230_004835.jpg   3.1MB   0 downloads


Attached File  IMG_20171230_004841.jpg   4.02MB   0 downloads


Attached File  IMG_20171230_005642.jpg   3.27MB   0 downloads


Attached File  IMG_20171230_005635.jpg   3.47MB   0 downloads






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