DavidMil Posted October 1, 2018 Share Posted October 1, 2018 Hello everyone! Sorry I've been away for awhile. Getting old sucks! And that's all I'm going to say about it! Please don't groan because there is nothing left in the attic either. I do have a problem with a 1200XL I just bought on ebay... It works fine, but If I let it go into screen saver mode it always locks up on the second color shift. It locks up so tight that I have to turn the computer off to be able to use it again. It's not heat as I've been playing Defender and Montezuma's Revenge for hours without any problems. But if I walk away for a time it's always locked up in the screen saver mode when I get back. The unit passes all the 'CPS Super Salt Rev. A' tests. Can someone tell me what chips/circuitry is involved with the screen saver? Thanks in advance, David 3 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 1, 2018 Share Posted October 1, 2018 I believe the color shifting is part of the OS rom. I could be wrong. Anyway, so if you let it sit until it starts color shifting, you are saying the colors change twice and then don't change anymore and hitting a key or space bar, or even reset doesn't bring it back, it stays "frozen" until you power-cycle? No matter what program is running, or even in self test or with a BASIC cart plugged in? It's a stock 1200XL? What splash screen does it have, the Rev. 11 OS rainbow ATARI with the the Reserved ® circle or the Rev. 10 one without an ®, just ATARI? Actually, I don't think it goes into color cycling in self-test mode as I just sat here waiting for it to do just that with OS R.10 and I think it sat far longer than it should there before it normally start color cycling...I'm loading something else...I'm just wondering if it's a Rev. 10 bug. I don't recall ever leaving my 1200XL with Rev. 10 sit long enough to color cycle before I upgraded to 800XL MMU and 32-in1 OS and Internal BASIC. So I'm trying it out now... Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted October 1, 2018 Share Posted October 1, 2018 Cannot reproduce the lockup with my stock 1200XL with Rev10 OS. DavidMil, can you try POKE 77,128 from BASIC? (To make the attract mode happen immediately) 1 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 1, 2018 Share Posted October 1, 2018 (edited) Cannot reproduce the lockup with my stock 1200XL with Rev10 OS. DavidMil, can you try POKE 77,128 from BASIC? (To make the attract mode happen immediately) me either with my Rev. 10 on 32-in-1...just tried the POKE with REV. 10 and BASIC A cartridge,..working normal, no lock-upso maybe not a bug... Edited October 1, 2018 by Gunstar Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted October 2, 2018 Share Posted October 2, 2018 Hello everyone! Sorry I've been away for awhile. Getting old sucks! And that's all I'm going to say about it! Please don't groan because there is nothing left in the attic either. I do have a problem with a 1200XL I just bought on ebay... It works fine, but If I let it go into screen saver mode it always locks up on the second color shift. It locks up so tight that I have to turn the computer off to be able to use it again. It's not heat as I've been playing Defender and Montezuma's Revenge for hours without any problems. But if I walk away for a time it's always locked up in the screen saver mode when I get back. The unit passes all the 'CPS Super Salt Rev. A' tests. Can someone tell me what chips/circuitry is involved with the screen saver? Thanks in advance, David Does it only do this at COLD power up? What if you wait until this happens and press RESET? Does it again wait the same time before lock-up? Or, does it happen sooner? Could this be a heat related issue? Which chips are getting too hot? Quote Link to comment Share on other sites More sharing options...
DavidMil Posted October 2, 2018 Author Share Posted October 2, 2018 I believe the color shifting is part of the OS rom. I could be wrong. Anyway, so if you let it sit until it starts color shifting, you are saying the colors change twice and then don't change anymore and hitting a key or space bar, or even reset doesn't bring it back, it stays "frozen" until you power-cycle? No matter what program is running, or even in self test or with a BASIC cart plugged in? It's a stock 1200XL? What splash screen does it have, the Rev. 11 OS rainbow ATARI with the the Reserved ® circle or the Rev. 10 one without an ®, just ATARI? Actually, I don't think it goes into color cycling in self-test mode as I just sat here waiting for it to do just that with OS R.10 and I think it sat far longer than it should there before it normally start color cycling...I'm loading something else...I'm just wondering if it's a Rev. 10 bug. I don't recall ever leaving my 1200XL with Rev. 10 sit long enough to color cycle before I upgraded to 800XL MMU and 32-in1 OS and Internal BASIC. So I'm trying it out now... I tried changing out the ROM OS R10 for my prized OS R11. Same result. It's mostly stock, I did a Bob Woolley ClearPic (ver.128.3) so I could have s-video output (I do this on all my 1200XL's), but other than that, it's stock. Nothing seems to be getting unusually hot. I haven't tried it with Basic. I'm not sure that Basic does a screen saver. I think I'm going to do the extended super salt test and let it run all night to see what happens. I'll let you know... David Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted October 2, 2018 Share Posted October 2, 2018 (edited) david please list the chips in that 1200XL, CO numbers and all... there may be a mis match.... Edited October 2, 2018 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
DavidMil Posted October 2, 2018 Author Share Posted October 2, 2018 (edited) Cannot reproduce the lockup with my stock 1200XL with Rev10 OS. DavidMil, can you try POKE 77,128 from BASIC? (To make the attract mode happen immediately) I put my Basic cartridge in and it seems to be working fine (for the last 30 minutes). I'll leave it running all night. I had to get my 'Mapping The Atari' out to look up the attract mode info. Thanks, David Edited October 2, 2018 by DavidMil Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 2, 2018 Share Posted October 2, 2018 (edited) 1200XL has hardware Reset like the other XL and XEs which means that any lockup should be escapable from - though of course that doesn't mean you're guaranteed a stable warmstart with your program intact etc. Turn the volume up and listen if you get a click when you press Reset - if so then it means the OS is at least being run. I just checked - it looks like the 1200XL shares the bug of the earlier OS in that if the APPMHI pointer is set too high, you get an unrecoverable reset lockup situation as the OS in unable to open the screen. To manually create this situation - POKE 15,200 then press Reset. Later XL and XE should recover from this. This situation shoudn't occur other than by program error setting the pointer too high or some sort of memory corruption going on. My suspicion - possibly you have dodgy Ram and inactivity is causing it to lose it's contents - or - Antic does memory refresh so possibly it could be bad. Suggestion - try alternate Antic and/or Ram chips. Edited October 2, 2018 by Rybags Quote Link to comment Share on other sites More sharing options...
DavidMil Posted October 2, 2018 Author Share Posted October 2, 2018 1200XL has hardware Reset like the other XL and XEs which means that any lockup should be escapable from - though of course that doesn't mean you're guaranteed a stable warmstart with your program intact etc. Turn the volume up and listen if you get a click when you press Reset - if so then it means the OS is at least being run. I just checked - it looks like the 1200XL shares the bug of the earlier OS in that if the APPMHI pointer is set too high, you get an unrecoverable reset lockup situation as the OS in unable to open the screen. To manually create this situation - POKE 15,200 then press Reset. Later XL and XE should recover from this. This situation shoudn't occur other than by program error setting the pointer too high or some sort of memory corruption going on. My suspicion - possibly you have dodgy Ram and inactivity is causing it to lose it's contents - or - Antic does memory refresh so possibly it could be bad. Suggestion - try alternate Antic and/or Ram chips. I'll try the ANTIC chip first. If that fails, I've got enough 64K RAM chips to switch them all out (the current RAM chips are all Mitsubishi chips dated 8309). Thanks, David Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted October 2, 2018 Share Posted October 2, 2018 I'll try the ANTIC chip first. If that fails, I've got enough 64K RAM chips to switch them all out (the current RAM chips are all Mitsubishi chips dated 8309). Thanks, David I believe the 1200XL uses the older ANTIC, compared to the rest of the XL/XE's. C012296 (older) has a 7 bit refresh counter and works only with 64Kx1 DRAM with 128 cycle refresh. (2ms) C021697 (newer) has an 8 bit refresh counter and works with both 64Kx1 DRAM with 128 & 256 cycle refresh. (4ms) So I guess check what type of RAM/ANTIC combo you have in there. 1 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted October 2, 2018 Share Posted October 2, 2018 and that's why I wanted a run down on his chips... no way to know who tried to fix it by swapping wrong chip Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 2, 2018 Share Posted October 2, 2018 I thought the refresh counter 7/8 rows related more towards the number of rows the ICs needed refreshed rather than the actual timing. Original Antic design has 9 refreshes on most scanlines compared to later machines like C64 and Plus/4 which only provide 5 - of course the newer machines never had to use the 1970s tech DRams that Atari first had. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted October 2, 2018 Share Posted October 2, 2018 (edited) also don't forget to check for cold/broken solder joints and sockets that have corroded or have weak and possibly broken wipes... Edited October 2, 2018 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
DavidMil Posted October 3, 2018 Author Share Posted October 3, 2018 Some time during the night it locked up. It had white hearts and '@' scattered around the screen. Here's the info on the chips... U19 GTIA chip C014805-01 Date Code 8312 U20 ANTIC chip C012296D-22 Date Code: 8239 U14 MMU chip CO60609 Date Code 8251 DMPAL16L8LDY/JC RAM none found Date Code 8309 M5K4164ANP Not going to list the ROMS because it does it with two different sets of ROM chips... This board has sockets for 28 pin ROMS but only has only uses the 24 pin ROMS (the zero ohm jumpers are in the correct positions W6,7,8,9) but it is obvious that W11,12,13 once had jumpers but have been removed (no solder left in through holes). With the 'hearts' and '@' signs around the screen I'm thinking I've got a flakey RAM chip More doctor visits tomorrow and Thursday so I won't have a chance to change any of them out. I will try another ANTIC chip tonight though. Thanks to everyone for your help so far, David Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted October 3, 2018 Share Posted October 3, 2018 Some time during the night it locked up. It had white hearts and At first blush that sounds like an ANTIC issue to me. Do you have a spare you can swap in? Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 3, 2018 Share Posted October 3, 2018 Such characters onscreen could be bad Antic or the CPU getting into a runaway/crash/lockup situation due to faulty OS Rom. I'm also tending towards Antic as prime suspect. Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted October 4, 2018 Share Posted October 4, 2018 Get a copy of "Passionately" demo and let it run for an hour or 2. If it crashes, you probably have a refresh problem. Lots of programs run just fine with bad refresh. Bob 1 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted October 4, 2018 Share Posted October 4, 2018 Looked at the datasheet for the RAM: M5K4164ANP = Refresh Cycles 128.0 So it is the correct timing for the C012296 (older) ANTIC. Also test with "Encounter!" I have one ANTIC chip that shows noise/glitches, but most prominently in that game. Quote Link to comment Share on other sites More sharing options...
DavidMil Posted October 6, 2018 Author Share Posted October 6, 2018 (edited) I believe I have it fixed! Though we were all barking up the wrong tree! He's what I've done today: 1. Changed out the ANTIC chip with one of my spares: no difference. 2. Tried another ANTIC chip to be certain: still no difference. 3. Swapped out all the RAM chips: no difference. 4. Pulled the RAM out of my known good 1200XL: no difference 5. Replaced the 6502 with the one from my good 1200XL: no difference 6. Replace the GTIA with the one from my good 1200XL: no difference 7. Grasping at straws now I went ahead and replaced the Pokey and PIA chips: no difference 8. Replaced the MMU chip: no difference. In fact the problem was getting much worse and now when I turn on the computer I get an orange screen with the words " System Error: Code 9 (although the code number changed every time I rebooted the 1200XL). So I changed out both of the 158 chips and the 138 chip with chips from the good computer, but I still got the same system error screen. So I changed out the 375 chip and the 1200XL came up fine! I ran Super Salt on continuous loop for couple of hours without any problems. Put the basic cartridge in and did the POKE 77,128 and let that run for an hour, and finally played Montezuma's Revenge for awhile. Everything worked perfectly! I've got the basic cartridge in the machine now and I'm going to let it run all night. Now I've got all these chips from the bad 1200XL that I'm going to start installing in my good 1200XL to see if there could have been any more 'slighly' bad chips. But it's working now so thanks to all for the help! David Edited October 6, 2018 by DavidMil 5 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted October 6, 2018 Share Posted October 6, 2018 In fact the problem was getting much worse and now when I turn on the computer I get an orange screen with the words " System Error: Code 9 (although the code number changed every time I rebooted the 1200XL). Wait, what? Were you testing with some kind of diagnostic cartridge installed or something? Quote Link to comment Share on other sites More sharing options...
DavidMil Posted October 6, 2018 Author Share Posted October 6, 2018 No cartridge installed. As soon I hit the power switch that orange (actually it was a yellowish orange color) comes up instantly. I can put the chip in my good 1200XL and see what happens. If the same screen comes up I'll take a pic and attach it to the this thread. David 1 Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted October 6, 2018 Share Posted October 6, 2018 No cartridge installed. As soon I hit the power switch that orange (actually it was a yellowish orange color) comes up instantly. I can put the chip in my good 1200XL and see what happens. If the same screen comes up I'll take a pic and attach it to the this thread. David I think DrVenkman was referring to the error code "System Error: Code 9 " That isn't something Atari's normally do. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted October 6, 2018 Share Posted October 6, 2018 David It's pretty cool to show the pictures, and the fellows here will prolly want dumps of chips and dig down to where and why the error would print. I love you digging this stuff up. Still providing an ejamacation after all these years. -Doc Quote Link to comment Share on other sites More sharing options...
DavidMil Posted October 6, 2018 Author Share Posted October 6, 2018 I think DrVenkman was referring to the error code "System Error: Code 9 " That isn't something Atari's normally do. I understood what he was asking, and I am well aware of the unusual screen that came up instantly when I turned on the machine. The first time it happened I felt for a cartridge in the side of the 1200XL too. I have never seen or heard of that error screen. Has anyone ever seen or heard of it? David Quote Link to comment Share on other sites More sharing options...
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