reifsnyderb Posted Sunday at 10:48 PM Share Posted Sunday at 10:48 PM 11 minutes ago, AtariGeezer said: Please do a double look on that! PAL A, pin 14, is labeled "NOT INTMPE" which should show as an Input that is fed by U8 Pin 8. U8 Pin 8 is where "NOT INTMPE" is generated. U8 Pin 9 is the MPE input. On both 1400xl and 1450xl schematics shows U11 Pin 18 (Originating MPE signal) gong to U8 Pin 9. --> Both can not be wrong... Good catch. I was thinking it didn't matter what the pin was called, as long as the logic worked. However, that triple NAND gate inverts the logic. Here's the corrected PAL A. PALA.PLD PALA.jed Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Sunday at 10:50 PM Author Share Posted Sunday at 10:50 PM (edited) 16 minutes ago, AtariGeezer said: Please do a double look on that! PAL A, pin 14, is labeled "NOT INTMPE" which should show as an Input that is fed by U8 Pin 8. U8 Pin 8 is where "NOT INTMPE" is generated. U8 Pin 9 is the MPE input. On both 1400xl and 1450xl schematics shows U11 Pin 18 (Originating MPE signal) gong to U8 Pin 9. --> Both can not be wrong... By the board truth U11 pin 18 is not generating the MPE signal. We know that since there is no trace from pin 18. So in this case the schematics are wrong. MPE is actually coming in on the PBI bus pin J3pin 43. But then again it sure seems like NOT INTMPE is being created twice. Might the schematic be wrong again? Edited Sunday at 10:58 PM by Dropcheck Quote Link to comment Share on other sites More sharing options...
reifsnyderb Posted Sunday at 10:57 PM Share Posted Sunday at 10:57 PM 2 minutes ago, Dropcheck said: You're arguing a non-issue. MPE/MPD is not generated internally. So far I am seeing it on R120pin1, PBI J3pin43 and the Parallel Drive Connector J12pin25. Which makes sense since that is a signal unique to an external connection on the PBI. It is coming in from the PBI externally connected device and then is handled by internal circuitry. The truth is the bare board tracing. Not the schematics which are obviously wrong in several others instances and are obviously wrong here. The PAL equations info we have are just a starting point, not the truth. We have just a few scraps of info, schematics and otherwise left of a prototype board that finally got to a pre-release version. Who knows what version of that process is reflected in the physical proto boards. I think @AtariGeezer was pointing out that PAL A's MPE/MPD related input goes through that triple NAND gate. So it is an internal MPD of sorts. Since it goes into PAL A, which functions like a normal XL MMU, the MMU logic treats it as an MPE/MPD signal. R120 should be the hold-up resistor on that MPE/MPD line. The truth will be in the bare board tracing, of course. Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Sunday at 11:00 PM Author Share Posted Sunday at 11:00 PM 1 minute ago, reifsnyderb said: I think @AtariGeezer was pointing out that PAL A's MPE/MPD related input goes through that triple NAND gate. So it is an internal MPD of sorts. Since it goes into PAL A, which functions like a normal XL MMU, the MMU logic treats it as an MPE/MPD signal. R120 should be the hold-up resistor on that MPE/MPD line. The truth will be in the bare board tracing, of course. Sorry was editing my previous statement after a few seconds of thought. Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Sunday at 11:03 PM Author Share Posted Sunday at 11:03 PM Have just verified on the board that U8pin8 and U12pin14 are tied together. Could it be different events triggering a different signal? Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted Sunday at 11:07 PM Share Posted Sunday at 11:07 PM Just now, Dropcheck said: Sorry was editing my previous statement after a few seconds of thought. Okay, I see your point. After looking at my PDD schematic, it does show MPE being generated by that board... So then your schematic was made by tracing out the 1450xl bare board? Quote Link to comment Share on other sites More sharing options...
reifsnyderb Posted Sunday at 11:08 PM Share Posted Sunday at 11:08 PM 1 minute ago, Dropcheck said: Have just verified on the board that U8pin8 and U12pin14 are tied together. Could it be different events triggering a different signal? My thought is the DipTrace schematic you posted makes sense. U8/8 going to U12/14 makes sense as U8/8 is taking the 3 inputs from MPD/MPE, D0, and D1 and setting the output low if all 3 of those signals are high. (D0 and D1 are those 2 lines going from U11 to U7.) The logic behind D0 and D1 make sense to be combined with MPD/MPE. Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Sunday at 11:11 PM Author Share Posted Sunday at 11:11 PM 4 minutes ago, AtariGeezer said: Okay, I see your point. After looking at my PDD schematic, it does show MPE being generated by that board... So then your schematic was made by tracing out the 1450xl bare board? Yes. 1 Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted Sunday at 11:13 PM Share Posted Sunday at 11:13 PM 2 minutes ago, reifsnyderb said: My thought is the DipTrace schematic you posted makes sense. U8/8 going to U12/14 makes sense as U8/8 is taking the 3 inputs from MPD/MPE, D0, and D1 and setting the output low if all 3 of those signals are high. (D0 and D1 are those 2 lines going from U11 to U7.) The logic behind D0 and D1 make sense to be combined with MPD/MPE. I concur, I have less of a headache now Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted Sunday at 11:20 PM Share Posted Sunday at 11:20 PM 6 minutes ago, Dropcheck said: Yes. Okay, is there any voltage checks you still need now? I have my 1450xl on the desk today... Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Sunday at 11:44 PM Author Share Posted Sunday at 11:44 PM 19 minutes ago, AtariGeezer said: Okay, is there any voltage checks you still need now? I have my 1450xl on the desk today... At this point not much is going to happen until I get kheller2's working board in Wednesday. After that I may need to verify with you on some things if I can. 😀 Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted Monday at 12:01 AM Share Posted Monday at 12:01 AM 14 minutes ago, Dropcheck said: At this point not much is going to happen until I get kheller2's working board in Wednesday. After that I may need to verify with you on some things if I can. 😀 Of course milady Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Tuesday at 10:16 PM Author Share Posted Tuesday at 10:16 PM hkeller2's board came in today, as well as the Mouser order. I found another two minor errors that I can fix easily. RP1pin4 should be connected to ~IRQ1 signal and C66 is not connected at all. Should be +5V on one end and GND on the other. I have received new PAL2GAL files from tf_hh that I'll burn and try out on my board then. As well as reifsnyderb's. Between the two we should have a valid set. If that does not bring up my board, then I'll dig into comparing hkeller2's board powered signals with my board. 1 Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Tuesday at 11:27 PM Author Share Posted Tuesday at 11:27 PM I fell out of my chair! It booted! Crappy picture. I can fix that. No knowing what else is or isn't working, but it is booting into BASIC. I don't want to breath too hard, I might jinx it. I fixed the RP1pin4 pullup signal on ~IRQ1 and C66. I decided to try tf_hh's files first, burned them into the GAL16V8 dip chips I had and inserted them into the board. And crossed my fingers. Then flipped the power button. IT BOOTED! I think kheller2's board scared it into working. I'm taking the rest of the night off. I think I've earned it. 😃 9 1 1 Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted Wednesday at 01:26 AM Share Posted Wednesday at 01:26 AM (edited) 1 hour ago, Dropcheck said: I fell out of my chair! It booted! Crappy picture. I can fix that. No knowing what else is or isn't working, but it is booting into BASIC. I don't want to breath too hard, I might jinx it. I fixed the RP1pin4 pullup signal on ~IRQ1 and C66. I decided to try tf_hh's files first, burned them into the GAL16V8 dip chips I had and inserted them into the board. And crossed my fingers. Then flipped the power button. IT BOOTED! I think kheller2's board scared it into working. I'm taking the rest of the night off. I think I've earned it. 😃 Pure awesomeness 🤩 Congratulations on being the first to re-create this piece of Atari History and bring it to life 👍 👍👍 Can we start the preorder for the bare board now? I'd buy two 🤑 Take your well deserved rest first... Edited Wednesday at 01:27 AM by AtariGeezer 2 Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Wednesday at 09:40 PM Author Share Posted Wednesday at 09:40 PM Well the board isn't quite ready for prime time yet. I have done a few more tests today. I wanted to start with the basics first. Once I have those nailed down, then I'll start with the speech chip and modem. It's turning out to be a little more delicate than I had anticipated. Since there is no case, I'm having to balance the loose 1200XL keyboard and top cover over the bare board and try like hell not to knock it off it's paper box spacers and down on the live board. That wouldn't be very much fun. 🙃 So far: SIO appears to work. Using an XF551, I was able to boot and load into memory DOS 2.5 and then bring up the DOS menu. Still to test is whether I can manipulate disks and use other devices on the SIO port. Cartridge port appears to work. I was able to load MULE from a cartridge. I'll try other cartridges over the next couple of days. But either I have wonky 1200XL keyboard or there is an issue with the 1450XL circuitry for the keyboard. I was not able to consistently get keys pressed to echo to the screen. The OPTION button worked once. The other buttons START and SELECT aren't at all. I am getting a power light on the current 1200XL keyboard. I'll have to partially disassemble my other 1200XL to try it's keyboard next. Sound is working. No apparent problem there. Video needs to be clean up a bit, but no artifacts or dropping out of sections of screen, so ram appears to be okay. Have verified the 1450XL will boot with either the normal Freddie or Lotherak's Freddie CPLD by Candle. Joysticks are still a bit unknown yet. I don't have another game cart to try right now that only uses joysticks and not the OPTION/SELECT buttons too. I thought about trying a disk-based game and I'll see if I've got something in my archives. RF out is not tested yet. I'm having problems finding my RF cable. PBI is not tested yet for much the same reason. I can't seem to find the one or two PBI devices I have. I put them away somewhere and I've forgotten where I put them. 😔 I'll update as I resolve missing equipment and the keyboard issue. But it is looking good. Eventually I plan a video to show proof of function. It's just going to take a few days yet. 5 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted Wednesday at 09:41 PM Share Posted Wednesday at 09:41 PM 22 hours ago, Dropcheck said: I'm taking the rest of the night off. I think I've earned it. Oh hell yes you do!!! 🍺 Congratulations!!! Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted Wednesday at 09:54 PM Share Posted Wednesday at 09:54 PM Please feel free to use my board with your keyboard as a comparison. It's probably just the keyboard. You can also run the SuperSalt tests. I'm also curious if we have finally nailed down proper PAL/GAL conversions. Now.. if anyone with the floppy board for the 1450 is around and would allow us to reverse engineer it too! Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted Wednesday at 09:57 PM Share Posted Wednesday at 09:57 PM (edited) any 75 ohm cable with rca on one end and f connector / adapter should be fine is you can't find yours. You can even do that with quad shield cable tv/satellite cable and adapters if you absolutely have no other avenue. It will be extremely stiff and unwieldy if you have to do that though. Edited Wednesday at 09:59 PM by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted Wednesday at 10:25 PM Author Share Posted Wednesday at 10:25 PM 26 minutes ago, kheller2 said: You can also run the SuperSalt tests. I'm also curious if we have finally nailed down proper PAL/GAL conversions. On the PAL/GAL conversions, I have not had a chance to test reifsnyderb's files yet. And I haven't been able to fully test tf_hh's yet. So that is also still up in the air. Added to the test list. I'd have to say probably tf_hh's PALtoGAL for PAL A is good. As I get to the speech and modem tests, I'll know more. Quote Link to comment Share on other sites More sharing options...
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