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setting up and fixing TI-99/4a & P-Box: PART 1



I recently got a beige TI-99/4a with a bad keyboard. Fortunately got it real cheap.  The problem it had was just a few keys worked. So I took it apart, checked the keyboard, the traces and everything looked OK. Posted the issue on the forum and it was suggested the keyboard processor was bad. A few weeks ago at the ATX TI fest I got a new processor and I have just now gotten around to installing the new keyboard processor and.... the new processor is worse off then the old one. the computer just hums and never comes on. Uck.

To test this I put the old keyboard processor back and it just did what it did before with just some of the keys working. So, the new keyboard processor is indeed bad. oh well.

What I did accomplish is put a socket in the slot to make testing the processor easier. At least I got something done, mostly.

My 1st attempt at adding a socket to the motherboard of the TI-99 went bad. I burned up some of the traces. You learn by experience. fortunately I had another motherboard and got the solder right on this one. 

When I get a new processor everything should work. 


Now the PEB. I bought a fully loaded PEB from Eric Olsen over the weekend at a really good price. thank you, Eric. He seems to think it all works but hasn't been tested. I can't wait to start working on the thing. I even got a P-Code card in it. Along with; fire hose connector, TI memory, RS232, TI-drive card and TI full high drive. Thing weighs a frikin' ton. 

I plan to add a Lotharek drive to the thing. would also like to install a speech model in the PEB if I can get or make up a card. 


I will blog as I work through this project and add pictures where I can. should be fun. 



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