Results 1 to 7 of 7

Thread: a hypothetical cpu (z80) replacment

  1. #1
    Great Puma (Level 12) Niku-Sama's Avatar
    Join Date
    Aug 2005
    Location
    Deadford, OR
    Posts
    4,129
    Thanks Thanks Given 
    5
    Thanks Thanks Received 
    63
    Thanked in
    59 Posts

    Default a hypothetical cpu (z80) replacment

    ok so I have been eyeballing MVS single slot PCBs on ebay for a while and I am tempted to get a bare board with some problem, cheap, and take a whack at fixing it. obviously trying to stay away from acid damaged boards.

    there on on the ebays, its a little much for my tastes but its an early single slot board I've been looking for with controller ports, memory card expansion slot and headphone out already on board for roughly $40. it says something about a z80 error and its non op. could be a bad cpu, possibly bad ram. theres no acid damage, or apparent acid damage in the pics and they are clear pics.

    heres the hypothetical...

    I have a master system with a cracked PCB and more broken traces that I can count. if I flex the board the right way I can get it working and aside from the cracks its a working board but theres no way I can track down all of the broken traces on both sides od the pcb and get it working with out some tom foolery, at this point its a donor board for a non working system but would it be possible to take the z80 off of the master system and use it as a replacement for the MVS?
    basically are they pin compatible?

  2. #2
    ServBot (Level 11) Custom rank graphic
    Graham Mitchell's Avatar
    Join Date
    Feb 2004
    Location
    Los Angeles, CA
    Posts
    3,623
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    1
    Thanked in
    1 Post
    Xbox LIVE
    Psygnosis8
    PSN
    Psygnosis8
    Steam
    Psygnosis8

    Default

    Quote Originally Posted by Niku-Sama View Post
    ok so I have been eyeballing MVS single slot PCBs on ebay for a while and I am tempted to get a bare board with some problem, cheap, and take a whack at fixing it. obviously trying to stay away from acid damaged boards.

    there on on the ebays, its a little much for my tastes but its an early single slot board I've been looking for with controller ports, memory card expansion slot and headphone out already on board for roughly $40. it says something about a z80 error and its non op. could be a bad cpu, possibly bad ram. theres no acid damage, or apparent acid damage in the pics and they are clear pics.

    heres the hypothetical...

    I have a master system with a cracked PCB and more broken traces that I can count. if I flex the board the right way I can get it working and aside from the cracks its a working board but theres no way I can track down all of the broken traces on both sides od the pcb and get it working with out some tom foolery, at this point its a donor board for a non working system but would it be possible to take the z80 off of the master system and use it as a replacement for the MVS?
    basically are they pin compatible?
    I would just get a new z80. They still manufacture them. A friend and I replaced one on a Psycho Soldier PCB and it worked fine.

    Edit: http://www.jameco.com/webapp/wcs/sto...SEARCH%252BNAV
    They have some here. Just try to match up the part number on the MVS chip. If you do some research, you can probably find one that's backwards compatible with the one in your MVS board as well.
    Last edited by Graham Mitchell; 10-23-2015 at 09:20 AM.

  3. #3
    Cherry (Level 1) Guntz's Avatar
    Join Date
    May 2011
    Location
    Canada
    Posts
    221
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Default

    Quote Originally Posted by Niku-Sama View Post
    ok so I have been eyeballing MVS single slot PCBs on ebay for a while and I am tempted to get a bare board with some problem, cheap, and take a whack at fixing it. obviously trying to stay away from acid damaged boards.

    there on on the ebays, its a little much for my tastes but its an early single slot board I've been looking for with controller ports, memory card expansion slot and headphone out already on board for roughly $40. it says something about a z80 error and its non op. could be a bad cpu, possibly bad ram. theres no acid damage, or apparent acid damage in the pics and they are clear pics.

    heres the hypothetical...

    I have a master system with a cracked PCB and more broken traces that I can count. if I flex the board the right way I can get it working and aside from the cracks its a working board but theres no way I can track down all of the broken traces on both sides od the pcb and get it working with out some tom foolery, at this point its a donor board for a non working system but would it be possible to take the z80 off of the master system and use it as a replacement for the MVS?
    basically are they pin compatible?
    "Z80 error" is a generic error in the MVS BIOS. It is not very specific and can be caused by a bad M1 ROM on the cartridge, bad connection between Z80 CPU and M1 ROM on cartridge, bad connection between Z80 and YM2610, broken YM2610 chip, broken Z80 chip or a few other things.

    If you decide to buy that MVS board, you should get a diagnostic kit from Jamma-Nation-X.com, it'll make repair a lot easier.

    Come join us on Micro-64

  4. #4
    Great Puma (Level 12) Niku-Sama's Avatar
    Join Date
    Aug 2005
    Location
    Deadford, OR
    Posts
    4,129
    Thanks Thanks Given 
    5
    Thanks Thanks Received 
    63
    Thanked in
    59 Posts

    Default

    Hmm that's kinda cool. Are there any multi carts with diag stuff in them?

  5. #5
    celerystalker is a poindexter celerystalker's Avatar
    Join Date
    Sep 2014
    Location
    St Louis, MO
    Posts
    2,816
    Thanks Thanks Given 
    3
    Thanks Thanks Received 
    16
    Thanked in
    14 Posts

    Default

    With multicarts, be wary of what model board you use, as there are compatability issues, largely with the earlier boards, which sound like the ones you're watching. You probably want an MV1-F or later for multicarts.

  6. #6
    Pretzel (Level 4) APE992's Avatar
    Join Date
    Jun 2007
    Location
    Chico, CA
    Posts
    999
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts
    Xbox LIVE
    APE992

    Default

    Have you tried to verify that the z80s are identical to each other in terms of instruction compatibility and pinout? There are multiple versions of the 68k, for example, that aren't 100% identical even though they claim to be. There are also the 68010, 68020, and 68030 out there. IIRC the 68030 is pin compatible but processes instructions more efficiently allowing for better performance but it isn't perfectly compatible and won't work with some Genesis games.

    With new z80s I just don't see a point in salvaging one. Sounds like you've got a fun project SMS though.
    Last edited by APE992; 10-24-2015 at 11:27 PM.
    I fix things. You name it, I'll work on it. Want something modded? Recapped?

  7. #7
    Great Puma (Level 12) Niku-Sama's Avatar
    Join Date
    Aug 2005
    Location
    Deadford, OR
    Posts
    4,129
    Thanks Thanks Given 
    5
    Thanks Thanks Received 
    63
    Thanked in
    59 Posts

    Default

    Yea fun.... At a time where people are demanding stupid high prices on replacement systems

Similar Threads

  1. wtb replacment panasonic q dvd drive
    By TheN64Guy in forum Buying and Selling
    Replies: 0
    Last Post: 02-03-2012, 12:32 PM
  2. Where to buy replacment GC control sticks.
    By CDiablo in forum Technical and Restoration Society
    Replies: 0
    Last Post: 03-01-2009, 02:28 PM
  3. Hypothetical problem: SNES image tearing on HDTV
    By Ed Oscuro in forum Classic Gaming
    Replies: 22
    Last Post: 07-11-2003, 07:44 PM
  4. Hypothetical question?
    By Captain Wrong in forum Classic Gaming
    Replies: 12
    Last Post: 07-03-2003, 09:06 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •