Jules Richardson wrote: That made we wonder... what's the oldest *operational* digital machine owned by anyone on this list? Although I suppose it's hard to define 'machine' - something with RAM, I/O in some form, and at least one CPU (what the heck do you call a CPU when it's no longer central?) I remember the discussions a while back about age of list members, but I don't recall ever seeing a similar one about age of collections! Not having all the peripherals that would have perhaps originally gone with the machine is acceptable I think (I can see some people having room for a mainframe and control desk, but probably not for a bazillion tape / drum units to go with it!). But other than that, make it complete (i.e. things like the single rack of EDSAC that we have - whilst perhaps "operational" - doesn't count :) (I'd quite like to hear responses from people with analogue machines too, but someone else will be able to define qualifying rules much better than I can) Just out of curiosity! cheers Jules I don't have the oldest, I'm certain, but to throw my hat in the ring: A Control Data 160-A manufactured in 1962. Has an Argonne Labs property sticker on it. Still has original manufacturing log showing all ECOs installed in factory and field. And of course it is still operational - several list members have seen it run. Internal paper tape reader and punch are operational. Has two external peripherals, 161-A I/O typewriter ( not working but in restoration ) and 167-2 Card Reader (Operational). There are a few vacuum tube machines out there, so surely there is one working someplace - an LPG-30, RPC-4000 or G-15? Those are all late '50's, so would qualify for oldest. By the way to answer someone's question, all of my equipment is transistor & diode logic. It predates ICs by several years. Core memory started with vacuum tubes (or valves, if you prefer), moved to transistors and finally ICs at the end of the era. I saw only a few commercial core memories with ICs. ICs meant RAM was feasible, so there was a very narrow window of Core and ICs. Many of those moved over to RAM in the middle of the production runs. I think I still have an ECS board that is a hybrid - can be built with either Core or RAM. I was told that the origin of Core was from looking like Apple slices after it had been cored. Apple corers were still available in the '50s and many homes had one. If you cored an apple, then sliced it, you get a disk with a hole cut out. I know my grandmother baked pies with both slices and wedges. The wedges in years of plenty, the slices in lean times. And dried apple slices were sold in the stores as a snack. Billy