PDP-12 on eBay

From: Gooijen H <GOOI_at_oce.nl>
Date: Tue Jan 14 01:25:00 2003

> -----Original Message-----
> From: Chad Fernandez [mailto:fernande_at_internet1.net]
> Sent: dinsdag 14 januari 2003 7:53
> To: cctalk_at_classiccmp.org
> Subject: Re: PDP-12 on eBay
> Look where Unisys is today :-( They mostly sell intel based
> stuff. I know a few years ago they still marketed some
> A Series machines, but I think it existed as a carry over
> from an earlier time.

I worked with SPERRY and later UNISYS 1100 machines. Big main frames.
They have a 36-bit architecture and the nice part of if is that you
can always read the octal dump, because a 36-bit word was always the
complete instruction. With "multi-byte" instructions in a dump it is
a bit more difficult to find the start of an instruction.
SPERRY had a character set called FIELDATA. It is 6-bit (uppercase
only), so you fit put 6 characters in one (36-bit) word.

Later, somewhere around 1989, they introduced the 2200, the smaller
version of the 1100, but runs the same instruction set.
I vagely remember that the 2200 line was called the "A-series", as
there was also a "B-series" as a result of the merger of SPERRY and
But, I am not sure. I left that company (and fine 1100) in 1990 ...

- Henk.
Received on Tue Jan 14 2003 - 01:25:00 GMT

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