Hello forum!

I have been working on a (real) DEC Rainbow 100-A (128K), and one of my challenges has been to dump the ST-506 drive that it came with. I ended up writing a disk dumping utility (based on disk-xfer)

MAME has been extremely useful to me during development, since I've been able to test nearly the entire process virtually before trying it on the real hardware.

I've been uploading binaries to emulated Rainbow via the virtual serial connection using kermit/lcterm, experimenting with various stuff using DEBUG.COM and eventually successfully running the entire disk imaging process on MAME.

Big thanks to everyone who has been involved with MAME and the Rainbow emulation!

Missing info from this thread

While reading this thread, I've spotted some stuff that seems really useful, but unfortunately doesn't seem to be available anymore.

Basically all the dropbox links are now dead, but I'm especially missing these ones, I think mostly from Bavarese:

  • Conversion RB100A to B (RBCONVRT.ZIP or RBCONVERT.ZIP) (github reference)
  • skew_unskew.7z
  • CODEBLUE_3.x_UPDATE_rev.20160804.7z
  • POST 3.1 FIXES-JAN-1990.7z
  • First_steps_Rainbow 100-B_January_2019_edition.pdf
  • anything bsdimp's disk collection that are not yet available in online archives

If the authors, or anyone else still has these files lying around on their hard drive, I would be very interested in accessing them!

Issues with MAME

Like I mentioned, MAME's Rainbow emulation has been very valuable. However, there are some stability issues. Here are some problems I've encountered:

  • Floppy access fails - (screenshot https://imgur.com/UTT1gn0) somehow only works on my debian virtual machine
  • Sometimes crashes - I should probably start running MAME under debugger to get some more information
  • Always crashes when re-connecting to serial port - but this can be worked around with a multiplexer


An older comment here says we're missing many of the language ROMS. I believe the ROM on my 100A might be the Finnish language ROM. I've dumped it using DEBUG.COM with the helpful instructions found here, and posted them online. I don't know if posting it here would break forum rules, but the sha1 is:

605a7a12b0c49445f76281203cbe7eed63d89222 rb100a-fi.e91