Monday, 8 August 2016

Tandy/Memorex VIS MD-2500

Usually, i just put here game consoles or systems that are usually not emulated from the first generation of video games, but this time it is a game system from the 4th generation ( system is pretty stretching it) called the Tandy/Memorex VIS (Video Information System) MD-2500.

To make a story short, this "wanna-be" educational system is now rare to find and sought after even if i would classify it as "Worst Game System EVER!!" but this is still part of the video game history and is also a great part about computer history since it has a "Modular Windows" for an operating system. Actually, it has a Windows 3.1 modified inside two EPROMS.

The BIOS of this system has two EPROMS labeled P513BK0B and P513BK1B which are 16-BIT (512K each in size) 27C240, and now these two EPROMS are now dumped but still need to be verified to see if both are good dumps. And if they are good then we need to wait that someone makes a driver for the MAME (MESS) to be finally preserved (Hey, even if i think it's the worst game system ever, it's still need to be preserved for historical purpose).

Here's a few pictures (and guts):

And pictures of the controller:

And here's a few screen shots of he BIOS in HEX (binary file) code:

And here's the link to the BIOS dump of the Tandy/Memorex VIS MD-2500

I will post soon scans of the VIS manual and Compton manual, until then take care folks! =)


  1. Your timing is perfect! I just picked up one of these today at a second-hand store, though mine didn't come with anything except for a copy of "The Secrets of Hosea Freeman" in the drive.

    If you ever get the the time in the future, it would be super helpful to also document the IR signals sent from the remote control and gamepads. I don't know if they use standard Memorex IR codes but the two-player nature of the pads makes me think that they are something proprietary to this console.

    If the codes were know then, hopefully, someone could build a SNES-to-VIS adapter to replace lost gamepads.

  2. Also, you may like to know, I opened mine and found there are some differences on the motherboard to yours. My serial number is 015287. Model number is the same.

    My motherboard has a barcode sticker next to the large brown slot with the numbers: "8859132 TP24992439"

    I have a ROM IC (not an EPROM, no window) in socket U36, and there is nothing in socket U35 next to is. There are solder pads, by no IC socket and no IC, just a placeholder. The ROM is labeled:

    (C)TANDY CORP 1992
    9242 AJ002

    In socket U1 (just below the large brown slot), I have an IC with a label on it that reads: "SFEB 10/16/92 8810405 2327"

    Also, my motherboard is darker brown colour.

    All other components look to be the same. The CD-ROM drive is the same model with the manufacturing date of November 1992.

    All this tells me you have a much earlier model, 4 months older than mine if the date on U1 can be trusted.

  3. For the record, the version of DOS in ROM here is DOS 3.22. (somehow managed to catch an int 21h ah=30h call in the MAME debugger)