[rescue] Personal progressions (was: what to do with a dec alpha 255)

Carl R. Friend crfriend at rcn.com
Thu May 31 19:27:51 CDT 2007

    On Fri, 1 Jun 2007, Geoffrey S. Mendelson wrote:

> [Paging has been] disscused before on this list. The first COMMERICAL
> machine to have paging was the IBM 360/67. DEC was working on it for
> the PDP-10, but did not sell it until later. One of the people who
> worked for DEC at that time joined the discussion and commented that
> it was a managment decsision.

    Is that supposed to be a capitalised "M" as in Dilbert-style
"Management"?  DEC had serious problems from the early 1970s on
concerning the -10 line from a "Management" standpoint.

> In 1977 I was working for a few months as a microcomputer
> consultant/systems analyst/programmer, and thought of adding paging
> hardware to the 8080 system I was working on, but like many of my ideas
> of that era, it never went beyond the thinking of it stage.

    Being a KI-10 bigot, and having seen the performance speedup of
MOS memory systems in the timing diagnostics, I began work in about
1982 or so on a cache for KIs.  It never came to anything, of course,
because not only was the KI-10 a dead duck, DEC scuttled the entire
pdp10 line in its "VAX uber alles" mantra.  The things that creative
folks could do with KIs are legion.

    One needs to remember that most well-designed systems in the 1960s
through the late 1970s were *well balanced*, not the "shove the
bottleneck around" monstoriciries we get today; balance was what let
an entire *system* function well as a cohesive whole, not just parts
of it.  Adding a cache to a KI-10, which operated with asynchronous
memories, would have yielded a massive performance gain, potentially
rivalling the later KL-10 implementation (run a KL-10 without its
cache and it's actually slower than a KA; been there, done that).

| Carl Richard Friend (UNIX Sysadmin)            | West Boylston       |
| Minicomputer Collector / Enthusiast            | Massachusetts, USA  |
| mailto:crfriend at rcn.com                        +---------------------+
| http://users.rcn.com/crfriend/museum           | ICBM: 42:22N 71:47W |

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