[Simh] Rainbow100

[Bill Cunningham]

  ----- Original Message ----- 
  From: Timothe Litt 
  To: simh at trailing-edge.com 
  Sent: Thursday, July 20, 2017 12:06 PM
  Subject: Re: [Simh] Rainbow100



  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".

  Ok go that from www.livingcomputers.org

  Bill
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20170720/37ebf084/attachment-0001.html>