[vcf-midatlantic] DEC Rainbow 100+

Adam Michlin amichlin at swerlin.com
Tue Mar 3 07:22:46 EST 2020

Interesting. This a video we took when first booting the machine:


No menu.

The Columbia link says it could potentially run 3 OSes:  MS-DOS, CP/M-86 
(16-bit), and CP/M-80 (8-bit). That would make sense with C:, D: and E:.

The plot thickens... I'll go through the manuals carefully at the 
workshop this weekend.

I haven't seen smooth scroll in decades, so I can't really say if it is 
different that what I know. It is beautiful, but I can imagine that the 
speed would get annoying with repeated uses.

On 3/2/2020 9:37 PM, David Gesswein via vcf-midatlantic wrote:
> Curious so looked a little. No first hand experience.
> Should have a boot menu
> https://thumbs.worthpoint.com/zoom/images4/1/0516/12/vintage-dec-rainbow-pc-100-b2_1_7450a211bd5a51daaf335136a45b64d8.jpg
> http://www.columbia.edu/cu/computinghistory/rainbow.html
> I always found the smooth scroll looked nice but was significantly slower than
> jump so I always turned it off. Is it any different on this machine?
> On Mon, Mar 02, 2020 at 08:23:32PM -0500, Adam Michlin via vcf-midatlantic wrote:
>> Hi Everyone,
>> So we have an absolutely gorgeous, looking almost brand new, completely
>> dec'ed out (see what I did there?), DEC Rainbow 100+ for hands on use in the
>> museum now in the new business office display.
>> It currently boots up to MS-DOS and runs the DEC WPS word processor. It also
>> seems to have 123 installed, although there may have a copy protection
>> issue.
>> But what intrigues me the most is that the MS-DOS boot disk is E:... C: and
>> D: appear to exist, but aren't MS-DOS formated.
>> So, I'm guessing these might be CP/M partitions for the Z80 processor also
>> in the DEC Rainbow. But, the big question, how do we tell it to boot CP/M?
>> And, I understand it can also function as a standand alone VT-100 terminal.
>> How do we get it to go into that mode? This opens an entirely different
>> world of uses once it is rotated out as the "business" computer on the
>> business desk.
>> Oh... most importantly... I had forgotten how absolutely gorgeous smooth
>> scroll is.
>> Thanks much,
>>            -Adam

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