Jump to content
IGNORED

Atari 5200 that works but doesn't?


walterg74
 Share

Recommended Posts

 

Continuing my streak of bad luck purchasing off ebay, I got a hold of a 2 port Atari 5200 that was supposed to be working fine, somthat I could have both models, as I already had a 4 port version.

 

I decided to test it today, and when I went to test the two games that it came with (breakout and pac-man) i found the following:

 

Pac-man showed the atari logo just fine and went to the title screen which showed some garbled characters, to the immediately go on to an even more garbled screen sand kind of be stuck at that...

 

I then proceeded tomtest breakout that on the other hand seemed to work fine?

 

Thinking it was just the cart, I then proceeded to test the atarimax cart, and while the burger time clone was looking good (although I thought I saw some glitchyness), testing the solitare game also brought along some weird characters (but not a lockup/freeze)...

 

I then brought out my previously purchased pile of carts, and testing them I found that roughly 60% of them seemed to work ok, but the others showed this garbling up of onscreen text and graphics a few seconds after power on...

 

Seeing that I took out my 4 port console and tested all the carts on it. They ALL Worked just fine...

 

So already talking woth the seller to see what can be arranged, but does a yone have a clue as to what could be causing this behavior, and this some work some don't thing?

Link to comment
Share on other sites

I don't know much about 5200 never having owned one however as the problem only exists with certain cartridges the console appears to be fundementally sound, one possibility could be a flacky external power unit/internal power regulator (if there is one).

If the effected carts require more current than the others and the supply drops low enough the unit could still function but the possibility of corruted data as 1's and 0's get miss interpreted increases.

I assume the power unit is the same for both models, if so try using your existing power unit on the 2 port model, if all games play ok with that then the power unit is likely to be your problem if not then could be internal power regulation but if it is not power related it may be difficult to resolve without the help of someone who if familiar the troubleshooting the 5200 or access to a copy the 5200 service manual.

Link to comment
Share on other sites

I usually start with cleaning the cart port. Sometimes it is just poor contact with the cart.

Ok tried the power supply of the working one, no good, issue still there...

 

Tried some cleaning, still there...

 

Weird thing also is:

 

- some carts seem to work fine

- some carts show corrups graphics almost immediately (i.e. Pac-Man)

- others seem to work for a while and then do it

 

Attaching a video of the last case

Edited by walterg74
Link to comment
Share on other sites

Ok, did more tests and really don't inow what to make of this...

 

From my pile of carts about 11 worked just fine (played a couplenof levels of ms pacman, galaxian etc. )

 

That miner 2049 if you leave the intro after the music and credits finish it'll grt f*ed up with garbled graphics and locked, but if you start the game I played two levels just fine.

 

And then there was another bunch about 6 others in my pile that get farbage locks almost immediately. Attaching screenshots, they are:

 

Pac-Man

Centipede

Space Dungeon

Countermeasure

Realsports Baseball

Pac-Man (second cart)

 

There doesn't seem to be any relation between 16KB or 32KB, and again, if I put these carts in my other 5200 they work flawlessly...

 

So again, same question: WTF?

post-31873-0-27887200-1456006640_thumb.jpeg

post-31873-0-30621900-1456006671_thumb.jpeg

post-31873-0-25557000-1456006689_thumb.jpeg

post-31873-0-47015300-1456006715_thumb.jpeg

post-31873-0-16260400-1456006754_thumb.jpeg

Link to comment
Share on other sites

Ok last batch of data...

 

I am a proud recent owner of an Atari Max Ultimate cart for the 5200 (in fact it came home with me along with this 5200).

 

With what is a disturbing consistency, the same carts that don't work in physical form, also exhibit the same symptoms when loaded as rom images with the Ultimate cart... (And the ones that worked also work with the Ultimate cart).

 

So It is definitely not liking those games that I'm guessing use some part of the 5200 that is broken..?

Link to comment
Share on other sites

Based on one repair I've done, I'm guessing there's a bad RAM chip. Some games could hit the bad memory location while others don't.

 

Given the resources you have at hand, I would swap out one RAM chip at a time with one from your 2 port machine.

 

The diagnostic program may detect it if you can run it. I didn't have that option at the time so can't vouch for the program.

 

Sent from my SCH-I535 using Tapatalk

Link to comment
Share on other sites

Thanks, I will give it a shot. I tried the diagnostics included with SD upUltimate as well as the diagnostics cart I had from the no-intro set, but either I don't know how to run it correctly or it's not detecting anything (one cart even said "testing 16K" and isn't it supposed to have more?

 

I will give this one a try.

Link to comment
Share on other sites

Based on one repair I've done, I'm guessing there's a bad RAM chip. Some games could hit the bad memory location while others don't.

Given the resources you have at hand, I would swap out one RAM chip at a time with one from your 2 port machine.

The diagnostic program may detect it if you can run it. I didn't have that option at the time so can't vouch for the program.

Sent from my SCH-I535 using Tapatalk

Thanks, I will give the cart option a try to see if it detects anything, and if not will see if I can try this suggestion. It is a pain in the butt though to take the shielding from the 2 port one. Not sure if the 4 port is the same.

Link to comment
Share on other sites

If you don't want to tear into the 2 port just yet, you could just try switching positions with the RAM chips in the 4 port.

If the behavior changes, you'll know something is up with the RAM. That is how I initially came to the conclusion that I had bad RAM before pulling a chip from another machine to definitively identify the bad chip.

Link to comment
Share on other sites

If you don't want to tear into the 2 port just yet, you could just try switching positions with the RAM chips in the 4 port.

If the behavior changes, you'll know something is up with the RAM. That is how I initially came to the conclusion that I had bad RAM before pulling a chip from another machine to definitively identify the bad chip.

Well it's the other way around actually, it's the 2 port the one that is faulty.

Link to comment
Share on other sites

Nope. The 5200 has 16k. It has tests for RAM, ROM, CPU, ANTIC and GTIA. Try them all and report back.Regards,Perry

Hmm ok, haven't gotten a chance to test it just yet, but it sounds similar to the test carts I already tried which had those, but I can't see any errors. Maybe I need to find proper instructions since I may be testing wrong?

Link to comment
Share on other sites

Hmm ok, haven't gotten a chance to test it just yet, but it sounds similar to the test carts I already tried which had those, but I can't see any errors. Maybe I need to find proper instructions since I may be testing wrong?

It's strait forward. Just press the test # and start to run a test. Start brings you back to the menu. I don't see anything in your reports that indicate there is a thermal issue, but it wouldn't hurt to run the test's, leave the machine running a while, then re-test. I was having problems with my 5200 and I found the CPU was getting flaky as it warmed up. It took about 1/2 hour before symptoms started.

Link to comment
Share on other sites

It's strait forward. Just press the test # and start to run a test. Start brings you back to the menu. I don't see anything in your reports that indicate there is a thermal issue, but it wouldn't hurt to run the test's, leave the machine running a while, then re-test. I was having problems with my 5200 and I found the CPU was getting flaky as it warmed up. It took about 1/2 hour before symptoms started.

Ok, giving it a try in a few mins...

 

BTW, re:your comment "atari has only 16k", so the bigger 32K carts were doing a whole lot of swapping..?

Link to comment
Share on other sites

Ok, giving it a try in a few mins...

 

BTW, re:your comment "atari has only 16k", so the bigger 32K carts were doing a whole lot of swapping..?

I'm not sure exactly what you are asking. The 6502 CPU has a 64k address space. In the 5200 the lower 16k is RAM. The middle 32k is for cartridge ROM. The upper 16k is for hardware registers and OS ROM. So the CPU could see the entire 32k ROM. No swapping is needed.

Link to comment
Share on other sites

Ok, giving it a try in a few mins...

 

BTW, re:your comment "atari has only 16k", so the bigger 32K carts were doing a whole lot of swapping..?

The 5200 has 16K of RAM. The 32K program on a cart doesn't necessarily get copied into RAM for execution.

RAM and ROM aren't directly connected that way.

 

You may be mixing up the concept of bankswitching as related to ROM cartridges. A system may, for example, only be able to directly address 32K of ROM. Using some additional hardware, you can effectively create additional address lines to allow addressing a larger amount of ROM (larger game program). If you can, through bankswitching trickery, switch on and off circuitry that represents just one more address bit, you can double the amount of ROM that you can access.

Link to comment
Share on other sites

Got it thanks to both. Definitely got confised and forgot carts have their own mem in itself.

 

Regarding testing tried that cart and thisnis what appears as seen in the attached screenshots.

 

Now I'm leaving for a friens's for lunch and left the atari on with the cart.

 

Will see if it's still good when I return and re-test.

post-31873-0-19089000-1456076052_thumb.jpeg

post-31873-0-22433700-1456076500_thumb.jpeg

post-31873-0-14951200-1456078273_thumb.jpeg

post-31873-0-56491600-1456080497_thumb.jpeg

post-31873-0-11391000-1456080592_thumb.jpeg

Link to comment
Share on other sites

  • 5 months later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...