So, I've been collecting images of 'Multics' 'front' panels from around the
Internet, intending to do a gallery.

(I should explain that, in common with mainframes of that era, a Multics
system had a variety of different kinds of boxes - CPUs, memories, etc - but
also others, intended to support the multi-CPU 'utility' concept. It was
possible to take, say, a running 3-CPU system, split off a CPU, bring that up
as a separate system, then later bring that down, and add it back to the
running system! This was actually done at the MIT site, to allow development
work in the evenings on the OS software.)

The Multicians site has a nice picture of a Multics system with the some of
the panels swung open (they're actually 'diagnostic' panels, so would normally
be swung shut):

  http://www.multicians.org/mulimg/h6180-doors-open-big.jpg

The CPU is the one in the center (the panel on the left is an IOM, 'I/O
Multiplexor', one of the other kinds of box).


So, anyway,I had this large collection of pictures, and asked: Tom Van Vleck,
the maintainer of the Multicians Web site what the other (non-CPU) panels on
offer might be, and his reaction was (roughly) 'some of the CPU panels there
might not be Multics CPU panels'.

(Honeywell had an entire line, the

  https://en.wikipedia.org/wiki/Honeywell_6000_series

but most models in that line ran an OS called GECOS (later GCOS), not
Multics. So possibly those CPU 'front' panels are from some other 6000 series
CPU.)

His reasoning was that they don't have the Appending Unit sections: to explain
this, Multics used an extra box (the Appending Unit), inserted between the CPU
and the memory, to implement the paging and segmentation of Multics, and most
6000-series CPUs did not have this.

If you look at this image of what is probably the Multics CPU panel now at the
LCM:

  http://ana-3.lcs.mit.edu/~jnc/tech/multics/jpg/_1020903.jpg

it has an Appending Unit section at the top. (BTW, are there any pictures
online of LCM panel? All I could find was the video, which is admittedly
ultra-cool.) See the "APU Scroll" section (first full-width section), for the
Appending Unit, at the top in this detailed shot:

  http://ana-3.lcs.mit.edu/~jnc/tech/multics/jpg/_1020899.jpg

It's not an extra panel: the CPU panel on a Multics machine, although the same
overall size, has a different configuration, with the APU sections.


However, the suspect CPU panels don't have those sections; see an image of one
here:

  http://ana-3.lcs.mit.edu/~jnc/tech/multics/jpg/multics_panel.jpg

with detailed images here:

  http://ana-3.lcs.mit.edu/~jnc/tech/multics/jpg/multics_panel_cu1.jpg
  http://ana-3.lcs.mit.edu/~jnc/tech/multics/jpg/multics_panel_cu2.jpg
  http://ana-3.lcs.mit.edu/~jnc/tech/multics/jpg/multics_panel_cu3.jpg

Which is not _definitive_ that they aren't from a Multics machine, but it
certainly raises a big question mark. So, the question is, 'are they Multics
panels, just for some reason without the APU section, or what'?

So maybe these are from some other Honeywell Series 6000 CPU? If so, does
anyone knows which Honeywell 6000 series machine (it pretty much has to be
from one of them) they are from?

     Noel

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