OS9dude
Experienced Member
After so many years I finally got my act together and jumped into the TI 99/4A wagon. Had a beat up machine inherited a couple of years ago which I had assumed was not working per the previous owner comments, the video modulator came badly corroded and with no grommets on the cables into it, power supply in equally bad physical shape; never took to installing the computer until today as I was testing a TI-99/4A I got delivered early morning.
The new unit is very well preserved, modulator in top shape as well as the accessory hardware it came with (voice module, cassette cable and joysticks). Upon installing it though I got a rather messed up video display:
To check if the modulator was OK I tested with the older beat-up computer, got the correct boot up screen on that one (surprisingly running, I did not expect it to as noted above).
The newer computer seems to be working, I can blind type into TI Basic and see the screen reflect some changes when it goes through those motions, once in Basic I can FCTN-Quit to what would be the master screen - looking as shown on the picture. If I let the computer on it will time out to the blank screen properly, and will come alive when pressing the keyboard.
Needless to say I have some snooping to do on the TI board, maybe a voltage in the video circuitry is out... time to hit the knowledge bases to find a schematic and proceed.
Any hints on how to go about this video problem will be welcome!
Thanks in advance.
-- RP
The new unit is very well preserved, modulator in top shape as well as the accessory hardware it came with (voice module, cassette cable and joysticks). Upon installing it though I got a rather messed up video display:
To check if the modulator was OK I tested with the older beat-up computer, got the correct boot up screen on that one (surprisingly running, I did not expect it to as noted above).
The newer computer seems to be working, I can blind type into TI Basic and see the screen reflect some changes when it goes through those motions, once in Basic I can FCTN-Quit to what would be the master screen - looking as shown on the picture. If I let the computer on it will time out to the blank screen properly, and will come alive when pressing the keyboard.
Needless to say I have some snooping to do on the TI board, maybe a voltage in the video circuitry is out... time to hit the knowledge bases to find a schematic and proceed.
Any hints on how to go about this video problem will be welcome!
Thanks in advance.
-- RP