An interesting 800XL problem...

[DavidMil]

A friend brought his 800XL to me a couple of days ago saying that except for the Break key, the keyboard

was no longer working. The computer boots to a ready prompt, loads DOS if a drive is attached, passes

both self test and Super Salt tests, and plays cartridge games without any problem (so long as no keyboard

input is required). The five function keys on the right work and the power LED lights up). Sounds like a

keyboard to me; but here is the strange part... if you hold down any key for awhile, the cursor will suddenly

drop down to the next line like its reached the end of line. It never moves to the right, you never hear the keyboard 'click', and nothing else

appears on the screen. If you move the cursor down enough times the READY message will scroll up off the

screen. I'm thinking either Pokey, GTIA, or possibly Basic. Let me hear any suggestions you all might have

before I order a replacement chip(s).

 

Thanks,

DavidMil

Kingwood, Texas

 

[Rockin' Kat]

I feel like the people who would be likely to answer this question are more likely to see it if you'd posted it to Atari 8-Bit forum section instead of the gaming general/hardware forum. I mean, obviously you can get answers here, but there are people who don't really leave the Atari specific sections much.

Edited December 26, 2016 by Rockin' Kat

[DanBoris]

A friend brought his 800XL to me a couple of days ago saying that except for the Break key, the keyboard

was no longer working. The computer boots to a ready prompt, loads DOS if a drive is attached, passes

both self test and Super Salt tests, and plays cartridge games without any problem (so long as no keyboard

input is required). The five function keys on the right work and the power LED lights up). Sounds like a

keyboard to me; but here is the strange part... if you hold down any key for awhile, the cursor will suddenly

drop down to the next line like its reached the end of line. It never moves to the right, you never hear the keyboard 'click', and nothing else

appears on the screen. If you move the cursor down enough times the READY message will scroll up off the

screen. I'm thinking either Pokey, GTIA, or possibly Basic. Let me hear any suggestions you all might have

before I order a replacement chip(s).

 

Thanks,

DavidMil

Kingwood, Texas

 

 

 

Sounds like a problem with the POKEY chip which does the keyboard scanning. The Start, Select, Reset and Option keys are handled by a different chip. The break key is handled by the POKEY but in a different way then the other keys which might explain why it works.