Friday, 12 August 2016

Tandy/Memorex VIS - 1st homebrewing attempt (and last ?)

After dumping the BIOS for the Tandy/Memorex VIS MD-2500, i was thinking if it was easy (or not) to rip or mod an existing game or even to port a DOS game. Well there is a good little shooter called "Spacenuts" on the Title Sampler (OK not that good but compared to anything for this system, it is good!) which i have tried to rip and make it self-bootable.

Only to say that my first three attempt have failed (can't make an omelet without breaking some eggs) but on my forth attempt..."Oh yeah Tabarnak!" (or Eureka!). It worked! And just to spice it a little, i have modded a word in the exec file (you need to watch the following video to know which word) and i also modded the spaceship sprite to look exactly like the spaceship in Vanguard.

The game is less than 1 megs, which is such a waste of space to burn on a CD-R, especially that these cost more than DVD's. But for a ISO to play on an emulator, this is a perfect file to try out (when it will be emulated in MAME of course).

After this, i tried to mod the game even more like almost change all the BMP files and WAV files so that it would have a better feeling of my all-time favorite arcade game Vanguard, which i called this new mod/rip: VISguard.

Well i was too eager to see he final results and after the boot screen...BANG! "Not enough memory to load wav files"...ahhh SCRAP!! Made a boo-boo! I didn't check the specs of the wavs to see it they were 11KHz or 22KHz, PCM, mono or stereo, etc...My bad! (like Cisco in The Flash series).

Here<s a few things i've discovered about the VIS: The BIOS has both Windows 3.1 and DOS (version ?) and the system is very, very close to a PC. So much that is is semi-compatible with the Tandy Sensation computers on the software level as some software needs drivers to be compatible and on the hardware, many parts like modem or video card are compatible (Sensation to VIS of course).

Software boots either in Windows mode or DOS mode by the help of a CONTROL.TAT (which is in fact an AUTOEXEC.BAT). When the software needs to boot in DOS, it has "a:\nameofexec.exe" before the MAKETAT text and if it needs to boot in Windows then it has "minwin a:" before the MAKETAT.

Videos are generally in AVI at 320x200 and files with the extension ".FUV" are in fact ".FLI" of ".FLC" (FLIC files, kind of a GIF animated file which are also at 320x200). In the "Title Sampler" CD, there is a SYSTEM.INI file which looks like it's been ripped from a PC:




WaveAudio=mciwave.drv you can see, it is more a PC than a edutainment system. And this idea has been copied over time like the RCA Studio II which is based on the RCA Cosmac VIP or the Atari XEGS, which is a 800XE computer disguised, just to name a few.

So i can't wait to see one day the Tandy/Memorex VIS emulated as i will pass the torch to anyone who wants to try to DEV this system since i have promised my VIS to a fellow game collector. I'm just have some fun with it before it leaves my hands forever.

Maybe i'll hang on to it a bit longer just to see what i can do with this thing, but that's  another story
and mystery !?!! =)


  1. Good afternoon Mr. Sly,

    My name is Mark Colbath. I began writing "Spacenuts" back in 1991. After a few months I was brought into the VIS development team as a software tester. I added features such as wav sounds and MIDI songs to the game. It became a tool that even the hardware team used to test with.

    Thanks for posting about it.

  2. Good afternoon..err night (as it's 11pm for me right now) Mr.Colbath,

    So you're the author of "Spacenuts" ? This is great because in all the games released for the VIS, yours is the most fun to play (and to hack have to!).

    Do you still have the sources of this game and the tools ? Because i've been asked by some people a kind a dev-kit for the VIS and nothing so far.

    Also, do have stories to tell about the VIS ? This would be so wonderful!

    Take care and keep in touch! =)