Re: 6-bit characters (was: Re: Streams in Ada)

["Marin David Condic" <marin.condic.auntie.spam@pacemicro.com>]

"Florian Weimer" <fw@deneb.enyo.de> wrote in message
news:87d7atkgrv.fsf@deneb.enyo.de...
> This page
>
>   http://www.montagar.com/dfwcug/VMS_HTML/timeline/1971-2.htm
>
Ooooooooohhhhhhhhhh!!!!!! Front-pannel switches and blinking lights! I feel
so nostalgic.


> seems to imply that DECsystem-10 and PDP-10 are different beasts.  The
> following page
>
I didn't get that impression. Just that "DECsystem-10" grew from "PDP-10" -
that it was mostly a naming issue & not one of any real fundamental
difference. There may be some technical distinction, but it seems of little
consequence. Same processor. Same instruction set. Maybe some evolutionary
differences, but that's true of all significant systems over time. (How long
have you been able to buy a "Ford Thunderbird"?)


> |  PDP-20 n.     The most famous computer that never was.  {PDP-10}
> |  computers running the {{TOPS-10}} operating system were labeled
> |  `DECsystem-10' as a way of differentiating them from the PDP-11.
> |  Later on, those systems running {TOPS-20} were labeled `DECSYSTEM-20'
> |  (the block capitals being the result of a lawsuit brought against DEC
by
> |  Singer, which once made a computer called `system-10'), but contrary to
> |  popular lore there was never a `PDP-20'; the only difference between
> |  a 10 and a 20 was the operating system and the color of the paint.
> |  Most (but not all) machines sold to run TOPS-10 were painted `Basil
> |  Blue', whereas most TOPS-20 machines were painted `Chinese Red' (often
> |  mistakenly called orange).

As I recall, the University of Chicago had a DECSYSTEM-20 - but I never
actually got to touch it. What I saw of the data on it tended to indicate
that it used the same KL-10 processor as the DECsystem-10. (KA, KI & KL were
the iterations of the processor I remember.)

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com
Web:      http://www.mcondic.com/