TI-99/4A

Atari, Nintendo, VIC20, Commodore, TI, Tandy, Kaypro, etc.
Post Reply
KenEG
Poster3
Poster3
Posts: 15
Joined: Wed Mar 25, 2020 3:35 pm

TI-99/4A

Post by KenEG »

Just putting this out there in case anyone else is interested. I recently bought 4 of these off eBay for about $100 after shipping tax, etc. Three of them had power supplies with them. I haven't tried the first one I bought because it sho0ws a lot of corrosion even without opening up. The other three that came with power supplies were one lot for $50 plus shipping. These were listed as "tested to power on", so I figured any damage caused by turning them on had already happened. I hooked each of them up and turned them on. The first one booted and I was able to go to basic.=, but only a few keys worked. The second one the same thing, but more keys worked. The third one actually works perfectly! I have since disassembled the second one and have all the keys working, except 'P' and 'space' are somewhat erratic. Sometimes it takes a hard press to make them work and others times they give multiple characters. I have a couple more things to try before I give up on fixing them. Worst case I will tear the keyboard down and move the defective switches to lesser used locations.

So anyone else on here have an interest in this machine? It was only on the market for 3 or 4 years, but 2.8 million of them were sold.
I never commit anything to memory because I can't rely on it. I write it down or print it out.
User avatar
chuckphd53
Moderator
Moderator
Posts: 301
Joined: Fri Mar 20, 2020 3:45 pm

Re: TI-99/4A

Post by chuckphd53 »

Would love to see a few pics !!!
“I never commit to memory anything that can easily be looked up in a book.” (AE)
KenEG
Poster3
Poster3
Posts: 15
Joined: Wed Mar 25, 2020 3:35 pm

Re: TI-99/4A

Post by KenEG »

OK here are some.
50FBD98B-E3F9-4560-B441-FB5F3183A903.jpeg
B50D01DE-C664-4C3A-B2F9-3D946C3607C5.jpeg
4509CCEA-4CEA-4A8A-A871-007510B77077.jpeg
You do not have the required permissions to view the files attached to this post.
I never commit anything to memory because I can't rely on it. I write it down or print it out.
User avatar
chuckphd53
Moderator
Moderator
Posts: 301
Joined: Fri Mar 20, 2020 3:45 pm

Re: TI-99/4A

Post by chuckphd53 »

AH not bad colors look good !

is that Video out put similar to the Jr ? RGB ?
I see it is on a flat screen so are you using a convertor ?
“I never commit to memory anything that can easily be looked up in a book.” (AE)
KenEG
Poster3
Poster3
Posts: 15
Joined: Wed Mar 25, 2020 3:35 pm

Re: TI-99/4A

Post by KenEG »

Don’t know why two are upside down. Trying again.
64150C27-3894-485C-887A-A37EEA2023F7.jpeg
0B95C8A8-EB4D-4865-BC04-66A455F0DCA3.jpeg
16 colors, one of which is transparent. It also has sprites. Transparent can be used with sprites and custom characters to let the background show through. Pretty neat for a computer made in 1981. It has a 16-bit TMS9900 CPU, but most of the memory and input/output is only 8 bit. Address buss is 16 bits, so 64k max without bank switching. Screen is 32x 24 character normally but there is a 40 column mode also.
You do not have the required permissions to view the files attached to this post.
I never commit anything to memory because I can't rely on it. I write it down or print it out.
Post Reply