• Please review our updated Terms and Rules here

Recent content by BradN

  1. B

    Successful Goldstar Green-screen mono Monitor Repair (with pictures!)

    Hi all, I just wanted to report a successful repair of a GoldStar MBM-2233 monitor, mfg. date Dec 1984. Click here for the photo album: http://imgur.com/a/27Dws Early symptoms: Randomly the horizontal picture width would twitch a little bit, this went on for some months. Total failure...
  2. B

    Yet another Sanyo MBC-55x thread?

    MBC-55x ROMs MBC-55x ROMs Here's a copy of the MBC-55x ROM in attachment. Use an 8 or 16KB ROM. If you use a 16KB one, duplicate the ROM to both halves for best results. I presume the CGA ROM could be replaced with an IBM PC CGA ROM, or you could even cook up your own font, or maybe even...
  3. B

    Flaw identified in Sanyo MBC-55x motherboard

    Hi all, I have discovered the cause of Sanyo MBC-55x boards that experience disk slow-downs and may eventually lose their ability to access the floppy drives: Part of the circuitry that generates a fake time delay in providing a "head loaded" signal to the floppy controller in response to the...
  4. B

    Packet driver services in BIOS

    Hmm, I did a little looking and it seems packet drivers use their own interrupt and don't require DOS - would there be anything stopping me from implementing say, SLIP or a similar serial protocol as a BIOS service?
  5. B

    Anyone have errata notes for intel 8251A UART chip?

    Hi, I'm getting to the point in writing my Sanyo MBC-55x BIOS that I'd like to create proper interrupt driven buffering serial port support, and I noticed that while the NEC 8251AC chip has a ton of hardware bugs, the intel chip was used on the serial board. The NEC chip is used on the...
  6. B

    Wanted: Sanyo MBC-55x accessories (cga, serial, hard drive, etc)

    If anyone has any accessories for the Sanyo MBC-55x series, I'd likely be interested. Things like CGA/RAM cards, serial UART cards, hard drive, or even interesting software that runs on it... I've already got 2 of the actual machines, so I probably wouldn't be interested in one unless it's...
Top