Newly acquired TI 99/4A - keyboard issue?

TI-99/4A Hardware problems, questions, etc.

Newly acquired TI 99/4A - keyboard issue?

Postby 58limited » May 12th, 2012, 10:33 am

Hi, I just bought a TI 99/4A system (silver case, black keyboard) with a PEB. There seems to be a problem with the keyboard and I'm not sure if it is a setting or if the keyboard is shot:

When I type the number keys in order from 1 to 0 it shows as 1 2 3 4 5 5 4 3 2 1 instead of 1 2 3 4 5 6 7 8 9 0.

I also noticed a couple of other keys either double strike or double strike with two different characters. Would replacing the keyboard fix this or is something else wrong? Maybe I should get another computer - the basic TI 99/4A is cheap on ebay, cheaper than some of the keyboards I see listed.

I had one of these as a kid, my dad was an engineer for TI and was on the design team. I spent hours playing games and doing some programming, but I have basically forgotten everything about these in the past three decades.
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby ksarul » May 13th, 2012, 10:43 am

Looks like a keyboard problem. Get a replacement keyboard and the problem should go away (I say should only because it assumes the replacement is without problems of its own).
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby 58limited » May 13th, 2012, 1:40 pm

Thanks. There is a working TI -99/4A on ebay for $10. I'll just buy that. A used keyboard listed on ebay is $25.00.

Another problem I have is the joysticks are not working. Getting another CPU unit will tell me if it is a computer problem or joystick problem. The PEB and tape drive (NIB) seem to be fine, using an old 12" color TV from 1983 as the monitor. Just won a memory expansion side car - for old times sake, I didn't have the PEB as a kid, just a few sidecars. Wish I still had the original set up - I started with a TI 99 then dad brought a 99/4A home. I had a prototype of the speech synthesizer. All were sold in a garage sale in the early 90s :(
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby Ben Yates » May 13th, 2012, 7:45 pm

Usual keyboard problems have to do with corrosion. Key-bounce (repeats), or nothing at all.
Remember that for joysticks, the Alpha-lock key has to be in the "up" position to register "up" on the joystick.

But your symptoms, if you are also having joystick problems, points to an issue with the Communications Register Unit, the TMS9901.

Ben
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby 58limited » May 13th, 2012, 7:51 pm

Thanks for the info. I had the alpha lock key set in the up position and got nothing. The person I'm buying the expansion side car from has a NIB TI 99/4A - just waiting for his price.
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby Ben Yates » May 14th, 2012, 5:37 am

Are these the standard TI joysticks? Atari-style do not work without an adapter.
If so, they do have an issue with the contacts - to me mine looked like the contacts were painted on. My 2nd pair (first was returned to TI as non-working right away), the contacts looked "dirty". I cleaned them, and after that they didn't work. I'd removed all the conductive paint.

Ben
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby 58limited » May 14th, 2012, 5:42 pm

The joysticks are TI brand and I have the box - Model no. PHP1100.
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby 58limited » May 25th, 2012, 7:13 pm

I got a replacement unit and all of the keys function normally. The joysticks do not work so I will get another set. The memory expansion side car is hooked up as is the PEB, which has one memory expansion card. I just bought a disk drive for the PEB but I need the disk controller card for the PEB. If anyone has one for sale, please let me know.
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby Ben Yates » May 26th, 2012, 5:28 am

58limited wrote:I got a replacement unit and all of the keys function normally. The joysticks do not work so I will get another set. The memory expansion side car is hooked up as is the PEB, which has one memory expansion card. I just bought a disk drive for the PEB but I need the disk controller card for the PEB. If anyone has one for sale, please let me know.


Don't run it with two memory expansions. Choose either the sidecar or the card.
As for disk controller cards, I have several, including TI brand.

Ben
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Re: Newly acquired TI 99/4A - keyboard issue?

Postby 58limited » May 26th, 2012, 5:42 am

Thanks for the reply Ben. Why can't the system run with both the side car and PEB?

How much are you asking for the TI brand disk controller card?
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