[Simh] Rainbow100

Thu Jul 20 13:31:20 EDT 2017

Gigi was a follow-on to the VT125, which introduced ReGIS.

Gigi was sold - and used - primarily as a graphics terminal, though it
does have a BASIC interpreter.  It was used on the DECSYSTEM-20 and
VAX.  There was some software support; Scribe had a driver for it.

I don't recall any BASIC software sold for GiGi - which would be
difficult, since GiGi has no mass storage - just two  RS232 ports; one
for host comm and one for either a LA34 printer or tablet.  with 16KB of
(D)RAM (plus screen memory) and  28K of ROM, there really wasn't much
you could do with it beyond its intended use as a terminal.  It was
thought that the EDU market might find a use for BASIC; but it wasn't
much of a thought.

CPU is an 8085 - less capable than the Z80, and not capable of running
any general purpose software - no CP/M, MS/DOS, or anything other than
the internal BASIC interpreter.

Someone sufficiently motivated might have driven one of the audio
cassette drives popular at the time (typically modem style FSK) off a
serial port.  But you'd have had to be very motivated.  GiGi wasn't
priced for the hobbyist.

I don't believe it predates the Robin - it was in 1982 (quite the year
for DEC PCish devices).

Again, I wouldn't classify it as a general purpose micro due to the
inability to load/save a program & the lack of software.

On 20-Jul-17 12:17, Johnny Billquist wrote:
> Timothe gives a lot of good info here.
>
> In addition, you also have the DEC GIGI, which I believe predates the
> Robin, and which I think also definitely would be classified as a
> "micro".
>
>     Johnny
>
> On 2017-07-20 18:06, Timothe Litt wrote:
>> On 19-Jul-17 23:23, Bill Cunningham wrote:
>>>     There's no simulator for DEC's first micro is there? Will there
>>> ever be one?
>>>
>>> Bill
>>>
>>>
>> That wouldn't be the Rainbow.
>>
>> There was the Harris/Intersil pdp-8 on a chip c.a 1975.
>>
>> The DEC/WD LSI11 c.a. 1976 followed.
>>
>> All these were in embedded systems.  The LSI-11 (and especially its
>> follow-ons, the T/F/J11) were used in a number of DEC's storage and
>> communications controllers, until ultimately replaced by VAXes.  (Yes,
>> your VAX probably had more VAXes in the IO subsystem than you knew
>> about.)  They were also very popular for third party embedded systems -
>> from volume copiers to airport landing lights.
>>
>> If by 'micro', you mean general purpose consumer packaged Intel
>> architecture machine, that would be the Robin (VT180), which is a Z80
>> CPU with dual 5 1/4 inch floppies, as a plugin board for the VT100.
>> CP/M.  Produced in the AD group, which Bob Glorioso managed at the
>> time.  Released c.a. 1982.  The board had its origin as a model railroad
>> controller created as a hobby project by an engineer in that group, and
>> was brought in and adapted for the VT180 as a quick time-to-market
>> product.  (I subsequently subsequently re-adapted the board for
>> something completely different - and learned the history a few years
>> later.)
>>
>> The VT103 used the same idea, but with an LSI-11 backplane and T11 -
>> TU58 tapes & RT11.  But it was later, and not on the IA path.
>>
>> The Rainbow was the replacement for the VT180 (c.a. late 82/early 83),
>> used RX50 diskettes and optionally, a st506 winchester drive.  It was
>> part of the triplet of machines, which also included the Pro 350 (pdp11)
>> and DECmate (PDP-8), that Ken Olsen pushed as the answer to the "cheap,
>> poorly engineered" IBM PC.  Besides being over-designed for the market,
>> all three suffered from being closed systems with hardware architectures
>> different enough from the standards (IBM PC/QBus/Omibus) to disable
>> commodity software.  Especially the Pro350, with its lobotomized P/OS
>> operating system (RSX with a horrible GUI) and limited menu of
>> application software.  (Eventually, RT was released, but too little, to
>> late.)  The DECmate never pretended to be anything other than a word
>> processor.  Ken's belief that quality would overcome price in this
>> market turned out to be very wrong.  And locking out existing software
>> made them niche products.
>>
>> Both the Rainbow and Pro got minor upgrades, then died.  The DECmate was
>> the most successful of the three in that it did exactly what it set out
>> to do; no more and no less.  It got larger winchester drives and some
>> minor software updates, but basically kept chugging along until
>> technology - Apple, WordPerfect (and eventually Word) - provided
>> bitmapped fonts.  (But lost the gold-key UI in favor of the mouse...)
>>
>> I don't think there was any real volume for the PC devices until the
>> DECstation IBM PC compatibles came along, which IIRC were
>> undistinguished Tandy buy-outs.
>>
>> And yes, the Z80 is a superset of the the Intel 8080, so perhaps you can
>> argue that it's not strictly IA.  But the Rainbow included one (you
>> could run CP/M on it, and it served as an I/O controller for the 8088).
>> And in any case, the VT180 fit the common definition of "micro" at
>> the time.
>>
>> In any case, by no definition was the Rainbow "DEC's first micro".
>>
>>
>>
>>
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