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Advice on Atari 800 Hardware Issue

atari 800 ram

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#1 gravislizard OFFLINE  

gravislizard

    Combat Commando

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Posted Thu Mar 28, 2019 10:36 AM

Hi everyone. I am hoping someone will recognize the issue I'm having with my Atari 800. I think I've narrowed it down to bad RAM, but before I spend any more money I'd like a second opinion.

 

The machine was given to me by a friend who had had it in storage for many years. The plastic chassis was destroyed and I had to disassemble and rebuild it, but the PCBs are all intact and the machine started and was able to run BASIC and other cartridge-based software perfectly. I was also able to load a game from cassette a couple times, though the belts in the cassette decks I was sent degraded rapidly and that stopped working.

 

I recently bought an SD2SIO, and the machine came with an Indus GT. I set to testing these this week, but I can't get anything to load. The specifics of it are peculiar, though.

 

The SD2SIO is set up to load the menu immediately on startup. When I power on the machine, it hits the SD2SIO, spins for a moment, then loads the menu and shows the files on the card. At that point the machine freezes completely. I have tried every possible input - Ctrl+Arrows in particular - and nothing works. The System Reset button also does nothing, which leads me to suspect the CPU is completely hung. When I first tried this I chalked it up to not knowing how to use the SD2SIO and stowed it for a while.

 

I received a cable for hooking up the Indus GT and tried it out finally. I have several disks that should be bootable - a couple boxed games, some commercial applications and some user-created disks labeled as applications. In all cases, when I start the machine the Indus sets to work reading the disk and, for several of the titles I've tried, succeeds in getting a title screen up, but then either it prints an error message or corrupt graphics, the machine hangs, or the screen becomes garbled.

 

Obviously the disks could all be old and tired, but they appear to have been stored well in their original boxes and sleeves and my gut says it's unlikely that they're all bad. The errors are also 100% reproducible, they always fail in exactly the same way for each program. I have cleaned the heads on the Indus.

 

My hunch is that there's some bad RAM a few kilobytes in - since everything seems to load the application data okay but then fritzes out when trying to load content, I'm guessing there's good RAM where the base program code goes but something's fried up where the bulk data tends to get loaded in. The machine has a 16K stock Atari RAM cart and a 32K third party expansion. I've tried all combinations (just the 16K, just the 32K, and swapping the two) and it just changes the way the errors look.

 

My assumption is that the 16K RAM cart has a bad chip, that the 32K RAM cart is not wired in a way that lets it correctly replace the 16K (hence testing with that doesn't solve it), and that I just need to get a new 16K card and I should be golden. Let me know if you think I'm on the right track. Thank you! Here's some pics.

 

photo_2019-03-28_09-24-50.jpg

Card layout

 

photo_2019-03-28_09-24-52.jpg

SD2SIO (just hangs here)

 

photo_2019-03-28_09-27-19.jpg

photo_2019-03-28_09-27-22.jpg

photo_2019-03-28_09-27-25.jpg

What happens when I try to load some of the disks I have

 

photo_2019-03-28_09-24-45.jpg

What happens when I try to load a couple programs that appear to have error handling

 

photo_2019-03-28_09-24-55.jpg

Funky RAM addon

 

 



#2 JR> OFFLINE  

JR>

    Moonsweeper

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Posted Thu Mar 28, 2019 11:41 AM

Try re-seating all the cards a few times.  Also, if you haven't already done so, remove the (basic?) cartridge and see if that changes things.



#3 GreyHobbit OFFLINE  

GreyHobbit

    Space Invader

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Posted Thu Mar 28, 2019 1:02 PM



 
The SD2SIO is set up to load the menu immediately on startup. When I power on the machine, it hits the SD2SIO, spins for a moment, then loads the menu and shows the files on the card. At that point the machine freezes completely. I have tried every possible input - Ctrl+Arrows in particular - and nothing works. The System Reset button also does nothing, which leads me to suspect the CPU is completely hung. When I first tried this I chalked it up to not knowing how to use the SD2SIO and stowed it for a while.
 
 


I have one of Lotharek's SIO2SDs that I was trying out with an 800 I bought recently. With 48K the menu hangs after loading, no keys work and after a few seconds there is some corruption to the screen.

It works perfectly with my 130XE so I assumed the SIO2SD menu needs an XL/XE. The 800 had 16K when I got it and I bought two 16K cards from B&C to bring it to the full 48K. I will try it on my 48K 400 and see if it locks up that machine the same as the 800.

Geoff

Sent from my ONEPLUS A3003 using Tapatalk

#4 Osgeld OFFLINE  

Osgeld

    Quadrunner

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Posted Thu Mar 28, 2019 1:24 PM

When I had a 400 (upgraded to 48k) it would do the same thing I used an older firmware on the sio2sd wiki and it was fine

Edited by Osgeld, Thu Mar 28, 2019 1:24 PM.


#5 gravislizard OFFLINE  

gravislizard

    Combat Commando

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Posted Thu Mar 28, 2019 1:34 PM

Try re-seating all the cards a few times.  Also, if you haven't already done so, remove the (basic?) cartridge and see if that changes things.

 

I have reseated the RAM cards multiple times but will try reseating the ROM as well, and I'll blow the slots out while I'm at it. I think I tried with and without the BASIC cart but will confirm.

 

I have one of Lotharek's SIO2SDs that I was trying out with an 800 I bought recently. With 48K the menu hangs after loading, no keys work and after a few seconds there is some corruption to the screen.

It works perfectly with my 130XE so I assumed the SIO2SD menu needs an XL/XE. The 800 had 16K when I got it and I bought two 16K cards from B&C to bring it to the full 48K. I will try it on my 48K 400 and see if it locks up that machine the same as the 800.

Geoff

Sent from my ONEPLUS A3003 using Tapatalk

 

Very intriguing input! I think I had simply assumed it worked with the 800 because it's listed as working with "atari 8 bit computers", but I hadn't explicitly searched for compatibility info. I did just now and came across another post here - wouldn't you know it, there are compatibility issues? This sounds like exactly what I'm experiencing. I'm excited to try the recommended change and the info linked later in the thread. http://atariage.com/...o2sd/?p=3442381

 

When I had a 400 (upgraded to 48k) it would do the same thing I used an older firmware on the sio2sd wiki and it was fine

 

Thank you, I will look for older firmware if the other techniques I've found don't work. Do you know which firmware you ended up with?



#6 slx OFFLINE  

slx

    Stargunner

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Posted Thu Mar 28, 2019 1:39 PM

You should also be able to use the SIO2SD without the boot menu, just emulating a floppy drive, by removing the program from the "Atari" folder and just putting .ATR files in there. You need to set D1: to some .ATR with a DOS or 800 compatible bootable game on it of course.



#7 gravislizard OFFLINE  

gravislizard

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Posted Thu Mar 28, 2019 1:57 PM

You should also be able to use the SIO2SD without the boot menu, just emulating a floppy drive, by removing the program from the "Atari" folder and just putting .ATR files in there. You need to set D1: to some .ATR with a DOS or 800 compatible bootable game on it of course.

 

Yeah, doing this it appears to all work. I did find a version of the menu XEX that loads and takes input on my 800, and I'm able to load a game (pole position) but when I go to pause it corrupts the screen and freezes, so I suspect the menu is leaving some junk in memory and is ultimately not (for whatever reason) compatible with my 800.

 

When I load Pole Position via the LCD on the device it appears to work perfectly though i haven't tried actually plugging in a joystick and playing yet.

 

I was also able to load SALT and run a 40K RAM test which passed, so all signs point to the machine itself being healthy and all my problems being the fault of a compatibility issue and very old, dying floppies (or maybe even the Indus itself). I'll continue testing but I feel like things are sorted.

 

Thanks everyone!



#8 gravislizard OFFLINE  

gravislizard

    Combat Commando

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Posted Thu Mar 28, 2019 3:21 PM

Can confirm for future seekers, the device appears to simply work when files are loaded via the LCD interface. I have loaded a half dozen applications and some games with no problems.



#9 ClausB OFFLINE  

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    Stargunner

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Posted Thu Mar 28, 2019 5:54 PM

Try opening up each RAM and ROM module and reseating each IC.

#10 Nezgar OFFLINE  

Nezgar

    Stargunner

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  • Location:Saskatchewan Canada

Posted Thu Mar 28, 2019 7:34 PM

Funky RAM addon


Trivia tidbit: Axlon was started by Atari cofounder Nolan Bushnell after he was fired from Atari by Warner management.

#11 ACML OFFLINE  

ACML

    Dragonstomper

  • 931 posts
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Posted Thu Mar 28, 2019 8:53 PM

Try these SIO2SD menus (earlier versions).  I actually like them better.

Attached File  sio2sd_v2.2.xex   4.56KB   18 downloads

Attached File  sio2sd_v2.5.xex   1.95KB   19 downloads

 

Also, I found that the 400/800 and SIO2SD work best when TOP DRIVE is set to OFF.

 







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