> -----Original Message----- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Chuck > Guzis > Sent: 15 July 2015 19:03 > To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off- > Topic Posts > Subject: Re: Reproducing old machines with newer technology (Re: PDP-12 at > the RICM) > > On 07/15/2015 10:35 AM, Paul Koning wrote: > > > > Then there was the very occasional early machine with no lights at all > > — the CDC 6000 series is the one I can think of. But there you had > > the real time console status display, which was even better — updated > > just as fast but with a whole lot more information. > > ...and that counters Neil's assertion that lights were too expensive. > Cray didn't use lights, neither did CDC as well as other manufacturers. > > What they used was (usually) a separate processor with diagnostic > capabilities. > > Lights and switches paled in comparison to what an intelligent diagnostic > processor could do--you could see the state of I/O channels, the P-counter > and the job to which it was attached, modify the status of just about > anything in the system and--in some cases even tell the state of the cooling > system. Some allowed the operator to degrade system memory, allowing > normal work to proceed using part of memory while performing diagnostic > testing on the other part. > > Lights are a quaint holdover from the 1950s and early 60s and really a cheap > alternative to getting system information. The console on a360/195 is an > example of the technology carried to a ridiculous extreme. The > minicomputers of the 70s with their lights and switches being the last > holdout, mostly because of cost. > > --Chuck
I rec all being told by an IBM'er that Amdahl had a patent on having a service processor, so IBM paid fees to Amdahl , but on investigation it looks like they had several:- http://patents.justia.com/assignee/amdahl-corporation?page=4 I also believe that Amdahl paid IBM for the use of the patents on Virtual memory. I wonder who paid most.... .. and perhaps this explains why IBM mid-range boxes did not have service processors... Dave G4UGM
