SNES Repro w/ 29f032 chip - FFIV (FFII USA)

Discussion in 'Modding and Hacking - Consoles and Electronics' started by jaskamakkara, May 28, 2016.

  1. jaskamakkara

    jaskamakkara Tinkering in the dark

    Joined:
    Aug 22, 2013
    Messages:
    140
    Likes Received:
    5
    I have been playing around with making SNES repros (using original Jap carts of the same games) using the m29f032 chips on the Type III adapters from buyicnow.com.

    I have successfully made a Chrono Trigger repro, but I got stuck with my FFIV one (that's FFII in the USA originally) - the Mask ROM on the FFIV cart PCB has 32 pins, while the m29f032 adapter board has 38 [edit - 36] pins and, as a result, doesn't fit.

    Should I simply snip the legs off the adapter for the "top 4 pins" (i.e. pins 1, 2, 37 & 38 [edit - 1, 2, 35 & 36]) and solder the rest of them in? Or is it just that the m29f032 chip cannot be used on PCBs with these "shorter" chips?

    I can, of course, use an M27c801 chip instead as the ROM is only 8Mb in size and the 801 has the requisite 32 pins - but that's not the point.

    Cheers
     
    Last edited: Aug 31, 2016
  2. sanni

    sanni Intrepid Member

    Joined:
    May 30, 2008
    Messages:
    653
    Likes Received:
    77
    Snip them off and rewire A21 and A20 to GND and WE to VCC.
     
  3. jaskamakkara

    jaskamakkara Tinkering in the dark

    Joined:
    Aug 22, 2013
    Messages:
    140
    Likes Received:
    5
    OK, thanks :) I started to take off the existing Mask ROM and I managed to break one of the caps on the board (because I'm a clumsy fool) - can anyone tell me what the capacitance of it was so I may replace it? I think the other one you can see in the picture has the same colour markings on it:

    (EDIT - I stuck the colour codes into a calculator online, and it says it's a 1.6µF cap - does this sound right? Not sure if I'm making out the colour markings correctly...)

    [​IMG]
     
    Last edited: May 29, 2016
  4. sanni

    sanni Intrepid Member

    Joined:
    May 30, 2008
    Messages:
    653
    Likes Received:
    77
    Those are just decoupling/bypass capacitors, you can replace them with standard 100nF ceramic caps.
     
  5. jaskamakkara

    jaskamakkara Tinkering in the dark

    Joined:
    Aug 22, 2013
    Messages:
    140
    Likes Received:
    5
    OK, thanks again for your help :)
     
  6. jaskamakkara

    jaskamakkara Tinkering in the dark

    Joined:
    Aug 22, 2013
    Messages:
    140
    Likes Received:
    5
    Just finished it and it works great :)
     
  7. Pikmin

    Pikmin Resolute Member

    Joined:
    Dec 23, 2009
    Messages:
    935
    Likes Received:
    95
    Can you please confirm that by using these boards you can only go up to 8 mbit in size?
     
  8. sanni

    sanni Intrepid Member

    Joined:
    May 30, 2008
    Messages:
    653
    Likes Received:
    77
    Every missing address line cuts the size in half, so without A21 it would be 16Mbit and without both A21 and A20 it would be 8Mbit. Or the other way around:
    2^22 = 4194304 bytes. (A0-A21 = 22 address lines)
    2^20 = 1048576 bytes (missing two address lines)

    Maybe you can rewire them manually, I have not testet that.
     
    Pikmin likes this.
  9. Pikmin

    Pikmin Resolute Member

    Joined:
    Dec 23, 2009
    Messages:
    935
    Likes Received:
    95
    Thanks for that. Yeah I've tried rewiring and it works but can get messy
     
  10. Mord.Fustang

    Mord.Fustang My goodness, it's nipley out!

    Joined:
    Feb 17, 2013
    Messages:
    818
    Likes Received:
    182
    Sorta off topic but what programmer do you use? Just curious.
     
  11. jaskamakkara

    jaskamakkara Tinkering in the dark

    Joined:
    Aug 22, 2013
    Messages:
    140
    Likes Received:
    5
    TL866 from eBay, with the adapters boards from buyicnow.
     
  12. Mobius_trip

    Mobius_trip Rapidly Rising Member

    Joined:
    Oct 28, 2015
    Messages:
    82
    Likes Received:
    24
    i have a question... i cannot find 29f032 in the tl866s chip list, i see that most used are ST and STs list doesnt contain it... what chip selection did you use to program?
     
  13. Bad_Ad84

    Bad_Ad84 The Tick

    Joined:
    May 26, 2011
    Messages:
    8,566
    Likes Received:
    1,309
    29f033 and disable ID check
     
  14. jaskamakkara

    jaskamakkara Tinkering in the dark

    Joined:
    Aug 22, 2013
    Messages:
    140
    Likes Received:
    5
    Set the programmer for the 29f033 chip (which the programmer IS compatible with), then disable the ID check.

    EDIT - ninja'd
     
  15. Mobius_trip

    Mobius_trip Rapidly Rising Member

    Joined:
    Oct 28, 2015
    Messages:
    82
    Likes Received:
    24
    bad_ad84 beat ya to the punch! hes always on top of everything! thanks for the tip, maybe i wont write off doing some snes repros...
     
sonicdude10
Draft saved Draft deleted
Insert every image as a...
  1.  0%

Share This Page