> -----Original Message----- > From: cctalk [mailto:[email protected]] On Behalf Of Noel > Chiappa via cctalk > Sent: 26 July 2017 15:38 > To: [email protected] > Cc: [email protected] > Subject: Honeywall mainframe CPU front panel ID? > > 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
>From what I remember, and it wasn't often you opened the panels on the L66 boxes, the systems all had almost identical configuration panels. All CPU's were upgradable on site to any other model. There wasn't really any difference between the models, the differences in performance were got by "marketing tweaks". So the bigger models had cache, and if you had two store boxes the memory could be interleaved. There was also a cache consistency feature. Later models also had virtual memory which I think used the MULTICs hardware.... .. so whilst its possible to say a panel is not from a multics box, I don't think its possible to say exactly which model it came from, and indeed as the CPU was upgradable the same panel could have been on multiple models. When I worked on one belonging to NERC, UK, it was upgraded from a single CPU L66/60 to a DPS300 and I am pretty sure none of these doors were not changed... Dave
