On Wed, Jul 26, 2017 at 7:37 AM, Noel Chiappa via cctalk < cctalk@classiccmp.org> wrote:
> 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 >
