walterg74 Posted February 19, 2016 Share Posted February 19, 2016 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? Quote Link to comment Share on other sites More sharing options...
+Stephen Moss Posted February 19, 2016 Share Posted February 19, 2016 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. Quote Link to comment Share on other sites More sharing options...
SIO2 Posted February 19, 2016 Share Posted February 19, 2016 (edited) I usually start with cleaning the cart port. Sometimes it is just poor contact with the cart. Edited February 19, 2016 by SIO2 1 Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 20, 2016 Author Share Posted February 20, 2016 (edited) 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 February 20, 2016 by walterg74 Quote Link to comment Share on other sites More sharing options...
7800fan Posted February 20, 2016 Share Posted February 20, 2016 Just wondering, are the carts working all 16k and the non working carts all 32k? Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 20, 2016 Author Share Posted February 20, 2016 Not sure where to get that info, searching here doesn't specifically say their size. These 2 examples of non-working ones: Pac-Man and Miner 2049er Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 20, 2016 Author Share Posted February 20, 2016 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? Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 20, 2016 Author Share Posted February 20, 2016 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..? Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 21, 2016 Share Posted February 21, 2016 Is there a diagnostic cart you could load onto your flash cart? edit: posted below Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 21, 2016 Share Posted February 21, 2016 Run this. Diagnostic Cart.bin Quote Link to comment Share on other sites More sharing options...
BigO Posted February 21, 2016 Share Posted February 21, 2016 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 Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 21, 2016 Author Share Posted February 21, 2016 Run this.Diagnostic Cart.bin 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. Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 21, 2016 Author Share Posted February 21, 2016 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. Quote Link to comment Share on other sites More sharing options...
BigO Posted February 21, 2016 Share Posted February 21, 2016 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. Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 21, 2016 Share Posted February 21, 2016 (one cart even said "testing 16K" and isn't it supposed to have more? Nope. The 5200 has 16k. It has tests for RAM, ROM, CPU, ANTIC and GTIA. Try them all and report back. Regards, Perry Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 21, 2016 Author Share Posted February 21, 2016 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. Quote Link to comment Share on other sites More sharing options...
BigO Posted February 21, 2016 Share Posted February 21, 2016 Oops. Well, I guess you could switch them around in the 4 port for practice. Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 21, 2016 Author Share Posted February 21, 2016 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? Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 21, 2016 Author Share Posted February 21, 2016 Oops. Well, I guess you could switch them around in the 4 port for practice. Lol sure, but if it aint broke... I guess I can just take the notches out Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 21, 2016 Share Posted February 21, 2016 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. Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 21, 2016 Author Share Posted February 21, 2016 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..? Quote Link to comment Share on other sites More sharing options...
tep392 Posted February 21, 2016 Share Posted February 21, 2016 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. Quote Link to comment Share on other sites More sharing options...
BigO Posted February 21, 2016 Share Posted February 21, 2016 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. Quote Link to comment Share on other sites More sharing options...
walterg74 Posted February 21, 2016 Author Share Posted February 21, 2016 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. Quote Link to comment Share on other sites More sharing options...
walterg74 Posted August 9, 2016 Author Share Posted August 9, 2016 Hey guys. Reviving this to see if anyone know anything woth those last shots I had psoted from the diagnostics? Also, If I were to need t change RAM chips, what do ai look for and where? Ebay? Quote Link to comment Share on other sites More sharing options...
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