[HELP!!!] Atari 130 XE Bad GTIA

[Hache]

Hi, I need help.
I am experiencing some graphical glitches on my Atari 130XE (PAL). I guess it will be the GTIA chip? Can anyone confirm? (Image attached captured from real machine)

The solution would be to replace it, I think. If so... Where to get a new replacement GTIA chip for the 130XE?

 

Thank you!

[Beeblebrox]

@Hache Whhoaaaoa - supersized Albert!!! 

 

I am assuming this is a stock 128K 130XE?

 

It may well actually be RAM related with one of the chips on their way out/imminently failing, especially if it is MT branded RAM. You get all manner of weirdness and then the next time you power up, it might be to a black or red screen. Open the casing up and carefully feel the RAM chips one at a time with a finger. If one or more are getting notably hotter than the others - they are failing.

 

Can you test other games and post pics of any glitches - visual or otherwise - you experience?

 

I am assuming your 130XE isn't socketed so if it turns out to be the RAM or the GTIA then you'll have to remove, socket, and insert new replacements. 

 

If its a bad GTIA depending on where you are based you can perhaps try and grab one on Ebay. TBH sometimes it's more cost effective, (if a little bit of a gamble), to find a broken or untested A8 XL/XE and take the GTIA from it. Then at least you'll have other spare parts and quite a few from the XL are transferable into the XE, especially the harder to come by 40pin chips, (CPU, ANTIC, GTIA, POKEY and PIA, (although latter can be replaced by a modern equivilent)).

 

Incidentally there are modern alternatives upgrades which replace the GTIA and give you a whole lot more functionality in terms of modern display connections, modes, etc - such as the Sophia /Sophia 2 boards - but as you may well have heard the latter are not being made at present due to the global chip shortage. (Likely 2024 before we can get our hands on a Sophia 2 board).

Edited May 3, 2022 by Beeblebrox

[Mclaneinc]

 

Wow, there are folks now looking at that sprite(s) and wishing they could recreate that bug

 

As for buying one, as said, Ebay or try the for sale forums on here, you may get a more favourable deal from a fellow Atari user as opposed to an ebay robber. Yeah, I know there are good sellers as well, but a quick scan of ebay looks more like some get rich scheme.

Edited May 3, 2022 by Mclaneinc

[Hache]

Thanks for all your help! I'made a video showing this problem (captured from real machine)

 

https://drive.google.com/file/d/1kODkq7_2Pxii6YzcOSrP-N5IuNuRWiyD/view?usp=sharing

[Rybags]

Try a cartridge game and see if you get similar result - something Rom based is less likely to have corruption if it's a Ram problem.

 

You could try some simple PM bars in Basic:

 

5 GRAPHICS 0
10 FOR X=0 TO 7:POKE 53248+X,60+X*16:NEX
T X
20 POKE 53277,0
30 POKE 704,52:POKE 705,184:POKE 706,136
:POKE 707,250:POKE 710,0:POKE 712,2
50 FOR A=53261 TO 53265:POKE A,255:NEXT
A

 

That should produce 8 bars - first 4 2 characters wide, the remainder 1/2 a character wide each.

[_The Doctor__]

Make sure the option key is working and you are booting with basic off,

perform some aggressive ram tests.