MVS cart replacing defective eproms.

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    • MVS cart replacing defective eproms.

      Hello guys first time posting here.

      I recent got some defective MVS carts to try to fix them, since I'm staring on modding/fixing stuff like that (I consolized my MVS board). Here in Brazil prices are usually high on some carts so I guess trying to fix the carts would be a good idea, so I bought some tools (for other projects as well) and a eprom burner (TL866 Mini Pro).

      Now the question, which Eprom to use in M1, EP1, V, C, S1 and P1/P2? I found that my burner reads the M1 rom with NEC UPD27C2001. so I bought some 27c2001 chips to repair a Fatal Fury 3 and a Real Bout (waiting for arrival)

      Did I bought the right eprom? What about the others? which one should I use? Also my adapter only has a 40 pin slot and some eprom has 42, anyone knows any adapter/converter for the TL866 Mini Pro?

      Sorry for so many questions and my bad english, I did some research but I really got stuck in this.

      Thanks in advance
    • aha2940 wrote:

      It depends on the game. If you tell us the games you are trying to repair, and which chip you intend to replace, maybe we can help you get the info you need to do it.

      Regards.
      At the moment I'm trying to fix Fatal Fury special with EP1 broken and I suspect P1 as well(but I can't read P1 since I don't have the 42 pins adapter yet), Fatal Fury 3 M1 with messed sound and Real Bout M1 with messed sound as well.
    • Hakeshu wrote:

      werejag wrote:

      m1 and s1 are 27c1000 and 27c1001 if i rememeber the 27c1001 is non jeda
      So 27c2001 is a non go? Since it was the option that I used to read the rom I tought it was the right one and already bought some. =(And whats is "Non Jeda"?
      You can use the 27C2001 chips, They work almost the same, just twice the size. It would not hurt if you googled the pinouts of those chips and a bit of how they work. JEDEC is a standard for creating the memories. Non-JEDEC ones have some pins on a different position AFAIK.
    • aha2940 wrote:

      Hakeshu wrote:

      werejag wrote:

      m1 and s1 are 27c1000 and 27c1001 if i rememeber the 27c1001 is non jeda
      So 27c2001 is a non go? Since it was the option that I used to read the rom I tought it was the right one and already bought some. =(And whats is "Non Jeda"?
      You can use the 27C2001 chips, They work almost the same, just twice the size. It would not hurt if you googled the pinouts of those chips and a bit of how they work. JEDEC is a standard for creating the memories. Non-JEDEC ones have some pins on a different position AFAIK.
      Thanks for the info aha2940. I did some research and got into this



































      So by this image I just need to swap the pins 2 and 24? I got a little confused by pin 30m since on 2001 its marked as A17 and on 1001 as NC. Just leave it like this or ignore this pin at all?

      Thanks one more time, I learned a lot with your information.
    • Hakeshu wrote:

      aha2940 wrote:

      Hakeshu wrote:

      werejag wrote:

      m1 and s1 are 27c1000 and 27c1001 if i rememeber the 27c1001 is non jeda
      So 27c2001 is a non go? Since it was the option that I used to read the rom I tought it was the right one and already bought some. =(And whats is "Non Jeda"?
      You can use the 27C2001 chips, They work almost the same, just twice the size. It would not hurt if you googled the pinouts of those chips and a bit of how they work. JEDEC is a standard for creating the memories. Non-JEDEC ones have some pins on a different position AFAIK.
      Thanks for the info aha2940. I did some research and got into this


































      So by this image I just need to swap the pins 2 and 24? I got a little confused by pin 30m since on 2001 its marked as A17 and on 1001 as NC. Just leave it like this or ignore this pin at all?

      Thanks one more time, I learned a lot with your information.
      That would be correct. You solder all the pins in their correct holes, but leave pins 2 and 24 lifted, then solder cables to them and the cables go to the respective holes. Easy as that. For the pin that says A17 on one chip but NC on the other, that's just the address line for the upper bit. You can simply solder it to ground, where it will always get a logical 0 signal and work fine. When burning the EPROM, you gotta use a file that is twice as big as the original ROM (original ROM is 1Mb in size, but your chip is 2Mb in size). To fill this extra space, just duplicate the actual rom into one file (concatenate the rom twice) and burn that file. That works fine if done properly.

      Regards.
    • aha2940 wrote:

      Hakeshu wrote:

      aha2940 wrote:

      Hakeshu wrote:

      werejag wrote:

      m1 and s1 are 27c1000 and 27c1001 if i rememeber the 27c1001 is non jeda
      So 27c2001 is a non go? Since it was the option that I used to read the rom I tought it was the right one and already bought some. =(And whats is "Non Jeda"?
      You can use the 27C2001 chips, They work almost the same, just twice the size. It would not hurt if you googled the pinouts of those chips and a bit of how they work. JEDEC is a standard for creating the memories. Non-JEDEC ones have some pins on a different position AFAIK.
      Thanks for the info aha2940. I did some research and got into this

































      So by this image I just need to swap the pins 2 and 24? I got a little confused by pin 30m since on 2001 its marked as A17 and on 1001 as NC. Just leave it like this or ignore this pin at all?

      Thanks one more time, I learned a lot with your information.
      That would be correct. You solder all the pins in their correct holes, but leave pins 2 and 24 lifted, then solder cables to them and the cables go to the respective holes. Easy as that. For the pin that says A17 on one chip but NC on the other, that's just the address line for the upper bit. You can simply solder it to ground, where it will always get a logical 0 signal and work fine. When burning the EPROM, you gotta use a file that is twice as big as the original ROM (original ROM is 1Mb in size, but your chip is 2Mb in size). To fill this extra space, just duplicate the actual rom into one file (concatenate the rom twice) and burn that file. That works fine if done properly.
      Regards.
      There's any specific program that do this rom expanson?
    • Darksoft wrote:

      Very simple, just lift the highest Adress lines and write in several times, forcing some lines to 0 or 1 :)

      P.S. Please update your profile with your location.
      Done with the location :) thought I already did that hahaha.

      Could you please explain about it? As I said I'm kind new to this stuff and I'm still trying to organize all the information that I'm getting 8| :D