Atari 600XL - its having a bad time... :(

[kevman3d]

Ok. The old Atari has started to do some odd things - it started when I got the SIO2Arduino project attached and working, I would get intermittent screen corruption, followed by the machine crashing.

I checked my wiring again with the Arduino, its all pretty much the same as the Spec's provided on the Whizzo software page. And it did work just fine, apart from the crashing. Since most disk games required more then 16k, I figured perhaps its having a bad time because the files just don't work. Odd thing to do if it runs out of RAM, but hey, I was pulling at straws... Occasionally the machine would start with a delay (and a buzz sound). I figured this was related to having a "Floppy disk" attached, but it wasn't frequent...

So I figured - maybe I should upgrade the machine to 64k. There were many, many, many guides to the same approach - I followed a few, double checked I'd done everything fine, and up she started.



Yes... And then No. It would crash after about 1-2 minutes with corrupted screen, which would just get worse and worse if I left it there - fonts get huge, blocks, random characters, etc, etc. I ran a memory test - it indicated that there was a problem at the 7th block in, got to the 8th block and locked up. Then it crashed with corrupted display again.

I decided to test a game cart - just in case - Dig Dug. Played fine... But every time I hit the 3rd level, it would crash and corrupt the screen. Sounded like possibly a ram issue if it was crashing at the same point. So I purchased some brand new 464 memory from china just in case the two I'd used were the issue... I swapped out the other 64k I'd been given and powered it on. Started straight away... Yahoo! But then after a minute or two - we're back to the corrupted screen, crash.

To make it worse, holding Option at start up wasn't working - it would just jump straight to the READY... Occasionally it would just lock up on a block cursor without READY - until I hit the Start key. Then it would crash again after a couple of minutes... Corrupted screen again.

I ran the DigDug cart again to test that the Option key was working. That keyboard ribbon and the connector on the PCB are a little fragile looking, but when it was working for the game it seemed to be just fine. The first time it ran fine for a game (I just left it to watch what would happen after a few minutes). I pressed Start again for a new game... The screen came up - then pow, corrupted...



I restarted, got the Dig Dug title screen, pressed start and once the screen popped up it corrupted, gradually displaying garbage bytes...



So a couple of restarts with Option held down - It took about 4-5 resets before I did manage to bring up the memory test - it got to the 8th block, then the screen corrupted again! As you can imagine, I'm now getting somewhat frustrated.



Anybody here got any thoughts on what could be buggered in here? A few places mention the ANTIC chip - which would make sense with the garbage display problem, but would it cause that short buzz/delay at the start before the READY cursor? Or the Option key doing nothing on boot?

Its a stressful mystery... If anybodies got an idea on what I can try next, I'd be greatful.

[Gibsaw]

<snip> it started when I got the SIO2Arduino project attached and working, I would get intermittent screen corruption, followed by the machine crashing.

I checked my wiring again with the Arduino, its all pretty much the same as the Spec's provided on the Whizzo software page. And it did work just fine, apart from the crashing. <snip>

... "apart from the crashing"...

Have you tried completely removing the SIO2Arduino stuff? It sounds like you need to eliminate that completely first. If the documentation you are following has any errors, then checking your wiring may not reveal the problem.

[kevman3d]

Have you tried completely removing the SIO2Arduino stuff? It sounds like you need to eliminate that completely first.

Oops! Maybe I didn't make that too clear... This is without the SIO2Arduino plugged in. I haven't plugged the Arduino back in for at least 3-4 weeks since I started to have issues. Its doing all of this on its own - the fact it doesn't do it immediately when its powered on makes me wonder what it could be... Even when sitting at the BASIC prompt, give it a few minutes and it'll begin to glitch out.

Given I could load a game off the Arduino (once I found a 16k one) and play it for at least 5-10 minutes before it crashed, I wasn't sure if the Arduino was at fault or perhaps its just an unfortunate coincidence that it decided to play up about the same time. I have an 800XL coming - but of course its staying in its box until this mystery is solved (just in case it is something that the device has done) - I'd rather not have two faulty machines.

Any thoughts?

[acsi]

Do you have any freeze spray?

Sounds like it could be a failing chip and freezing them one by one when the board is warmed up may help to identify it.

[tezza]

Just a thought. I had an Atari 800 once that kept blowing RAM chips, soon after I replaced them. Turns out it was a faulty PSU.
http://www.classic-computers.org.nz/blo ... i800XL.htm

Could this be the issue?

[kevman3d]

Do you have any freeze spray?

Nope. But I'm sure I could source some.

Just a thought. I had an Atari 800 once that kept blowing RAM chips, soon after I replaced them. Turns out it was a faulty PSU.

Ta for that... I'll check the voltages on the PSU on the weekend and find out if its got any odd issues. It started to happen just after I plugged in the Arduino.

I'll do another double-double check of that device too on the weekend. I hopefully didn't miss something when I checked it, or made an incredibly stupid mistake when I wired it up - I can imagine a small amount of voltage on the wrong pin could fry things... Also, I should probably test the arduino itself to make sure it isn't partially faulty (I just assumed it should be perfect... But you never know)

Oh well. I do have an 800XL coming at some stage, but definitely won't be plugging it in until I'm 100% sure of that PSU. This one is an American model, so I'll need that NZ PSU to run it.

[tezza]

Oh well. I do have an 800XL coming at some stage, but definitely won't be plugging it in until I'm 100% sure of that PSU. This one is an American model, so I'll need that NZ PSU to run it.

Just on that American model..Chances are it will have the chipset for NTSC not PAL, so you'll need to plug it into an NTSC-compatible monitor.

[kevman3d]

Just on that American model..Chances are it will have the chipset for NTSC not PAL, so you'll need to plug it into an NTSC-compatible monitor.

Don (who I've bought it from) did have a photo on Trademe showing it running using an NZ power supply. Hopefully should be all good, but thank's for the heads up in on that - I'll keep that in mind in case it doesn't appear to display anything... Though obviously I won't test that until I've checked my NZ PSU first of course to make sure its not going to fry anything.

[LilJoe]

Any updates? If it's any help I have a dead 800XL if you want to try swapping some ICs.

[kevman3d]

Any updates?

Nah, haven't gotten back to it as things just got too busy to play with the machines - I haven't actually touched the 800XL here either, though the paranoia of making it go 'pop' kinda makes me feel nervous to plug it in.

If it's any help I have a dead 800XL if you want to try swapping some ICs

That's a great offer - thanks... I'll let you know what happens and then pester you again if I find its a fried IC of some kind... One suggestion was the POKEY IC may be a problem... But until I get some time, then I'll probably not touch it again for a while...

I also have a Sega 3000 I need to toy with at some stage as well... So many things I want to do but so little time.