Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 7 of 7

Thread: [queued] ROM reader with teensy 3.5

  1. #1
    Junior Member
    Join Date
    Aug 2018
    Posts
    3

    [queued] ROM reader with teensy 3.5

    Hi guys,

    I have built a reader for old ROMs and uploaded the code here: https://github.com/Luz/sega-rom-reader

    The teensy 3.5 was used because its inputs are 5V tolerant. For the outputs, the 3.3V are also compatible with the TTL logic, since 2.4V is accepted as high.

    Here are some pictures:





    The "wire wrap"-technique was used because I love it.

  2. #2
    Senior Member+ Frank B's Avatar
    Join Date
    Apr 2014
    Location
    Germany NRW
    Posts
    5,679
    Wow... impressive.I like such retro projects very much!
    And a lot of work to do by hand!

    Nowadays the Chinese are so cheap and fast (and that with top quality) that I don't do that to myself anymore. Usually the circuit board is already shipped the next day.
    Besides, you usually get 10 boards, which I often give away

  3. #3
    Junior Member
    Join Date
    Aug 2018
    Posts
    3
    Yes, I have also made like 20-30 different pcb's, but I really like wire wrapping, and I wanted to have it faster than chinese
    Also I still have stuff to add to that project, so the pcb will still change a bit. Maybe I'll make a real pcb later

  4. #4
    Administrator Robin's Avatar
    Join Date
    Oct 2012
    Location
    PJRC Global Headquarters
    Posts
    312
    I'm not all that familiar with most game consoles. What do you do with the ROMs once you've read them?

  5. #5
    Senior Member+ Theremingenieur's Avatar
    Join Date
    Feb 2014
    Location
    Colmar, France
    Posts
    2,457
    Once read, one might either use the code in emulators, or simply duplicate them to build clones. The high school is analyzing and modifying the code to add cheats.

  6. #6
    Senior Member+ Frank B's Avatar
    Join Date
    Apr 2014
    Location
    Germany NRW
    Posts
    5,679
    For most of the old ROMS, so-called "ROM-LISTINGS" with dis-assembled code are available on internet. Nevertheless, it's a great project, esp. if you have a rare ROM version, or if it is not available for download.
    For C64, they used several versions, and even 3rd-party ROMs where available (for $$$). For the disk-drives (they had a CPU, too) were "turbo"-versions with higher transfer-speeds available. C64-Disk-drives were very slow that time.. mostly caused by a silicon-bug that needed a software-workaround for one of the c64-chips, so the originally commodore- intended hardware-supported transfers were not possible. Modern emulators try to mimic these bugs... (and for the sound-chip are VERY exact emulators available that emulate every little detail because many sound-effects relied on not-documented special clock-cycle dependend behaviour - the "reSID" is such a emulation)
    (Yes, even in the "good old times" there were silicon-bugs...
    Sorry for off-topic..
    Last edited by Frank B; 02-21-2019 at 09:19 PM.

  7. #7
    Junior Member
    Join Date
    Aug 2018
    Posts
    3
    Quote Originally Posted by Robin View Post
    I'm not all that familiar with most game consoles. What do you do with the ROMs once you've read them?
    The goal was to read the roms that I've programmed, but the programmer isn't finished yet.
    When reading/writing works, then comes the hardest part... setting up a toolchain for c -> asm

Posting Permissions

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