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Dizzy

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Posts posted by Dizzy

  1. Now my 1040 STE is failing again finding the floppy drive ... What is strange is that the floppy led lits, like if the STE had found the floppy and was trying to access it. But the Gotek display does not show the number of the selected slot, I have dashes instead ... I tried multiple USB sticks, same issue. I am now having a doubt on the Gotek, as it was working on my STF but some games failing to load. When my STE was working again, the same games were working fine. I am lost now !

     

    EDIT : I finally could test another Gotek on my 1040STE, and I have the same issue. So the problem comes for sure from my Atari ... bad news ...

  2. Now my 1040 STE is failing again finding the floppy drive ... What is strange is that the floppy led lits, like if the STE had found the floppy and was trying to access it. But the Gotek display does not show the number of the selected slot, I have dashes instead ... I tried multiple USB sticks, same issue. I am now having a doubt on the Gotek, as it was working on my STF but some games failing to load. When my STE was working again, the same games were working fine. I am lost now !

  3. 4 hours ago, ParanoidLittleMan said:

    Hmm, then it is some later revision for sure (1991-92) - because Ajax and square DMA were used in Mega STE .

    "Unfortunatly", now my Atari works fine again ... it is now working for more than one hour and still works fine ... I do not know why, maybe my Ajax reseat (and socket cleaning) solved the problem only later ? As I don't believe in miracles, I think it will come back to a bad situation soon, time will tell ...

  4. 6 hours ago, bfollowell said:

    It's been a while since I've had mine open. I guess I assumed that, since it looks like a standard floppy cable, that it had a standard connector on both ends. I didn't recall the motherboard end being soldered.

     

    I do know that the cable doesn't connect to a Gotek the same way that it connects to a floppy drive. You either have to twist the cable around upside down, or mount the Gotek upside down. It won't work any other way. Since yours was previously working, I must assume that either your cable, or your Gotek is inverted.

    Yes the ribbon has to be twisted for the Gotek to work. But my Gotek was working before failing, so I know there is no issue on this side.

  5. 11 hours ago, ParanoidLittleMan said:

    Ajax was used in Mega STEs (but not in all - for instance my is earlier model, and was with DD, not HD floppy drive), not in STE, because of HD floppy support. STE has no it.  But it may be that Atari had nothing else at hand, and put Ajax in some STEs.

    And ST DMA can work with floppies in STE. That's tested.

    No I cannot swap the STF DMA with my STE DMA : on my STE the DMA is a C398789-001 which is of a square shape and soldered on the motherboard (not socketed). On my STF the DMA does not have the same shape (rectangle).

  6. 11 hours ago, bfollowell said:

     

    No, you should have a floppy drive cable that connects on both ends.

     

    You haven't maybe removed the cable from your Gotek recently and forgotten to invert the cable when you connect to the Gotek have you?

     

     

    No I definitly confirm that the floppy data cable is soldered on the motherboard, which is normal (see this link https://www.ebay.com/itm/Retro-Atari-ST-Floppy-Power-Data-Cable-Extender-29cm-for-Gotek-Drive-Mounting-/123623525932 where it is confirmed that on Atari ST the floppy data cable is soldered, and I confirm that mine is soldered). No, I did not invert the cable on the Gotek. But thanks for your answers.

  7. 1 hour ago, ParanoidLittleMan said:

    Since you have working ST, it would be good to replace FDC chip in STE with one in ST. It will work well with DD format (720, 800K) .

    Actually, why is Ajax in STE ? Is there HD floppy mod in it ?

    And you can try with replacing DMA chip too. ST's one will be good for floppies in STE.

    Third chip what is involved in floppy work is PSG (YM) chip, but that's probably not socketed.  Hmm... maybe other 2 is not too ?

    Well, I guess no other way, after you done suggested simple error checks.

     

    I do not know if it was modded. Isn't the Ajax standard on a 1040 STE ?

    I cannot swap the DMA with my STF : the DMA is soldered on the motherboard and isn't the same kind as the one in the STF.

  8. 1 hour ago, bfollowell said:

    Possibly, but always check the simple things first. Assuming you have a meter, have you checked for proper voltage on the floppy power connector? Have you reseated both ends of the floppy data cable? Have you tried that cable anywhere else, assuming you have somewhere else to try it, to confirm that it is good?

     

    As ParanoidLittleMan pointed out in a recent post, all of our 16-bit equipment is easily 30 years old, and some is pushing 35. It's inevitable that things are going to start failing. Still, always check the simple things first, just to rule them out, if nothing else. Sometimes you'll come up lucky.

     

    If you do wind up needing an Ajax chip, a quick search came up with this seller on ebay in the U.S. Hopefully, you'll be able to find a seller closer to home.

     

    https://www.ebay.com/p/27025453844

     

    I could not see this item on ebay as I live in France, and when I ask to ebay to show me items worldwide, it only shows me the items which the sellers want to sell worldwide (local sells are not shown to me). Thanks for your link I will check if he agrees to sell worldwide.

    I guess the power is good as my Gotek and original floppy drive do start (leds are lit).

    For the floppy data cable, unless I am wrong, it is soldered on the motherboard of my 1040 STE. Isn't it ?

  9. Hello,

    since this morning, my 1040 STE does not read any games anymore. I loaded International Karate using my Gotek, just before the game started some bombs were displayed and the STE crashed. Since then, when I start my STE, the STE tries to boot the floppy (Gotek) then display the desktop but with no floppy icons (the desktop is empty), just like if no floppy drive was connected. I tested the Gotek on a 520 ST and it is working fine. So the problem comes from somewhere on the STE motherboard. I think the problem may come from the C302434 (AJAX) which is the floppy controler, I tried to reseat it but no luck.
    As the STE behave like if there was no floppy drive connected, do you think the issue may come from the C302434 ?
    If yes, do you know where I can buy one ?

    Thanks a lot !

  10. OK, so I will give the "expert" answer to myself : a brown screen at startup means that the Atari 800 does not find the OS ROM ... How do I know it now ? hummm .... well .... I feel very very very stupid ... When I was doing my last tests about CPU swaps, I did not put back the OS ROM into the Atari ... AAAArrrgghh !!!! Sooooo Stupid I am !!!!!!! :mad:

    So I re-did all my tests, the conclusion is : what was causing the Atari to crash after a few seconds of use (except when playing with games cartridges) was the 6502C on the CPU board.

    As I already ordered a new 6502C alone, I could swap it with my bad 6502C to let my CPU board work fine. So I ordered a new spare PAL CPU board for nothing ... :mad: I will have now to sell my working spare PAL CPU board ...

     

    Thanks to all of you for the help you provided to me !

  11. The problem is getting even more weird ... Here is what was the situation before today :

    - When I turned on my PAL Atari 800, the Atari was crashing after a few seconds of use, but only when using BASIC / NOTEPAD / or floppy disks. When I was running games cartridges, everything was fine.

    - When I swapped the CPU card from an NTSC Atari 800, then no crash anymore (except of course the displayed colors which were wrong due to NTSC/PAL incompatibility).

    - I tested ANTIC / GTIA, they seemed to work fine. So I ordered a new 6502C, but when I swap it I get a brown screen at startup.

     

    So I thought the problem may come from another component on the CPU board. So I finally ordered a new PAL CPU board. I tried it today, but when I startup the 800, I am still getting the brown screen !

    So I decided to put back the old PAL CPU board, and now I am still getting the brown screen at startup even with this board !!!!!!!

     

    I don't understand why the situation is getting worse ... Finally my problem does not seem to come from my CPU board, I now need help from an Atari 800 expert to tell me what means a brown screen at startup ....

    Anyone knows ?

  12. Just remember that you can NOT swap a 6502B and a 6502C (C014806) chip. It is perfectly acceptable to swap the entire CPU card (no matter which type CPU is on it), though.

     

    Yes, but I don't understand why I get the same result when swapping my 6502C with another 6502C, and when swapping my 6502C with a 6502B ... To me the result should be different, and I even more don't understand why the original Atari 800 6502C is working better than the 6502C of my Atari 800 XL ...

  13. Bad news ... the 6502C replacement did not solve my problem ... And I still cannot understand this strange situation :

    - If I replace the current 6502C by a 6502B (new one), then when I power up the Atari 800 I get a brown screen.

    - If I replace the current 6502C by a 6502C (new one), then when I power up the Atari 800 I get a brown screen (same result !).

    - If I put back the original 6502C, then the cartridges work fine, the only problem is when using basic or notepad : freezes after a few seconds of use ...

     

    So if the problem does not come from the CPU (or GTIA / Antic), why only the original CPU work almost fine (but not well) ?

     

    Anyway, now that I have a 800XL, can I swap the Antic / GTIA from it to insert them into the 800 ? (I don't think so as Rybags told me they are unic to each system...)

     

    I guess that now I will have no other choice than buying a new PAL CPU board ... Aaargh !

  14. The web page is horrible, but the parts are good :)

    http://www.best-electronics-ca.com/800.htm

     

    Thanks for this direct link ! 19.95$ is a good price, I sent another email, and had a resonse saying we need to order for at least 20$ ... I still do not know what would be the shipping cost but probably around 30$. So 50$ is a lot to pay, this is the exact price I paid for my PAL ATARI 800 (with a few accessories, box, documentation, cables, etc ...) which was a good price, I know ... So I am still waiting for to receive the Sally I ordered on Ebay (17€ shipping cost included) and still hope it will work. Of course, buying a whole cpu card would be safer.

    I will also pickup an Atari 800 XL I bought yesterday (but not to fix my 800 !).

  15. I already gave info where one place (Best Electronics) has UK/PAL 800 CPU boards. see earlier post in this thread.

    I know, thanks again, but this website is just horrible : different colors and underligned texts everywhere, you do not know where to click ... impossible to find what I was searching for : where do you see a PAL cpu card there ? I sent an email with no response. And even if they would have answered, the cost of the cpu card plus the shipping price for France would be too high I guess.

    PAL CPU cards are hard to find in Europe.

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  16. There is still something I cannot explain : I know the problem comes from the CPU board, but not from Antic or GTIA. So the last guilty processor may be the 6502, or a small electronic component (like a resistor).

    But I do not understand why a cartridge game works fine ? If my 6502C is bad, why does it work fine when intensively used for running a cartridge, why is it crashing when just typing a text in notepad or Basic ?

     

    It is a non sense to me, I really cannot explain that, does anybody has an idea of the differences in the CPU (6502) usage while running a cartridge game or while just typing a text in the notepad ?

  17. Thanks for your answer. Here is what is written on my 6502 :

     

    MOS

    CO14806-6

    0282

     

    I guess my 800 was a "recent" one as on the box there was a sticker "Now with 48K". So it's not one of the first releases.

    The 6502 chips I have on the NTSC CPU boards are 6502B. So you are right : my processor in the PAL 800 is a 6502C. This surely explain why when I was swapping my 6502C with a 6502B I had a brown screen ...

    Now I need to find one. I have some Apple IIe with a 65C02 processor, but I guess it is not the same as 6502C, right ?

  18. Thanks for your answer (I am in France but I can order anywhere in the world if they do international shipping). But I finally swapped my PAL ATARI 800 6502 with a PAL VIC20 6502, and I have the exact same result as when I swapped the CPU with an NTSC ATARI 800 :

    brown screen on power on ...

    So now I am pretty sure that there is no NTSC or PAL 6502. There is only one 6502 processor for both PAL and NTSC version (which is very logic to me).

     

    So now here is my very strange situation :

     

    - If I use the original 6502 of my PAL Atari 800, then after a few seconds of use in Basic or notepad, or while booting a floppy, it crashes (and the reset button don't even work). But it works fine using a cartdridge !!! (????).

     

    - If I use the NTSC 800 6502 in my PAL 800, then it just display a brown screen at startup ...

     

    - If I use the NTSC 800 complete CPU board in my PAL 800, then it works fine except it displays colored stripes (wich is probably due to the NTSC / PAL differences). So this confirms the problem comes from my PAL CPU board, but according to my different tests, the problem is not coming from the ANTIC, GTIA, or 74LS244N.

     

    So the only possibilites are that the problem comes from :

     

    - the 6502, but why other working 6502's are working worse than the original 6502 in my PAL CPU board ?

     

    - the 74LS74ANDS, but I have no spare part to try.

     

    - an electronic component like a resistor for exemple, but my knowledges in electronic are too low to know how to test them ...

     

    So I feel a bit desperate, as my only solution would be to buy a PAL CPU board .

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