18 May
2026
18 May
'26
5:43 p.m.
On Mon, May 18, 2026 at 12:27 PM Robert Armstrong <bob(a)jfcl.com> wrote:
Yes. That's the MSDOS version. I don't have the 2.05 version. PATCH.211
reads part of MSDOS off the disk (directly, since it knows it has to be in
specific spots forced by the rainbow's boot loader), then places
UNIV211.BIN into the image and writes it back out. As near as I can work
out, this replaces MSDOS' drive table (effectively the DEC hardisk driver
and linked list of driver blocks) with univation's.
I've never seen a 3.11 version. One could likely adapt the assembler I did
(since it assembles to the same thing) and do the porting / work out the
math on the patch. Since I never had working hardware, I never did that.
Warner Losh
<imp(a)bsdimp.com> wrote:
https://github.com/bsdimp/rainbow100.git has my efforts ...
Thanks, Warner! A couple of things - #1 my Rainbow actually turns out
to be a 100B after all. I just assumed it was the A model, but on closer
inspection I'm wrong. It's a 100B2 and even has the hard disk boot option
("W") on the menu. Doesn't work, of course - it just complains that the
drive is not ready. So this machine could support the DEC hard drive
controller, but apparently whoever bought it originally didn't want that.
I notice that your github has a UNIV211.BIN and a PATCH.211, where as my
Univation diskette has UNIV205 and PATCH.205. Is that by any chance the
MSDOS version? V2.05 or v2.11? Since I have a 100B I should be able to
run MSDOS 3.11 if I can find a copy of the Rainbow version; do you know if
there was ever a UNIV311.BIN, etc?
Univation did a nice job on the modification. The
half height hard
drive and an auxiliary daughter card (which I assume is the SASI to MFM
adapter you mentioned) fit nicely in an all around metal enclosure the size
of a full height drive. The drive itself is 20Mb and I wonder if it's a
plain old ST-225, but I haven't tried to disassemble the enclosure yet to
find out. It's still working, so I'm reluctant to mess with it.
Almost certainly a plain ST-225.... Mine was. I had to recover it with the
mfm emulator...
If you can put up the scans of your manuals
somewhere, I'd appreciate
it. And thanks again!
I'll find it and upload it or I'll scan it again. I'll see if I can rustle
up the kicab files I started on a million years ago when I was trying to
troubleshoot my card.
Warner