On Oct 7 2005, 12:51, Hans Franke wrote: well. [ ... ] :-) Well, I *was* demoing it to the organisers and senior staff... Final death toll was one KIM-1, the top 1K of my Commodore PET (one of the early ones with the nasty MOS Technology 6550 RAMs) and a Mac Plus which got rather unhappy midmorning. Probably all fixable in one way or another. "Thank you" to the various people who replied about the KIM. I never had time to look at it again this week, perhaps I'll have a go at the weekend. I did actually know about the site that several of you mentioned, and I also have the schematic and most manuals, just not handy at the time, so I was really just wondering if there was a common failure mode. The suggestion of using small components on the back, out of sight, is an interesting one, though, and the suggestions made about other methods may be helpful too. In other respects the tours for the students were a great success -- and the staff loved them. Some went and fetched their colleagues and came back with them! We had a display of generations of computing from a 1920s mechanical card tabulator through bits of ENIAC (valve), Pegasus (valve), LEO (transistor, well the last version was anyway), and various TTL-based boards (some SSI, some with 74181 MSI ALUs, etc) to LSI/VLSI ending up with an 8008 board (we don't seem to have a 4004 between us, surprisingly -- if anyone would like to donate one for next time, feel free ;-)). We had a display of three generations (densities) of core memory, static and dynamic RAM chips and SIMMS/DIMMS/etc, several generations of EPROMS (oh, and a diode ROM board) and a few chips to see under a fairly powerful binocular microscope. We had a whole range of drives and discs, from RK05 to modern SCSI,including some hard drives running with perspex covers, and all sorts of floppies, stiffies, flopticals and zips, and tapes from paper tape (one of the quiz questions was how much paper tape would it take to store the same data as you'd fit on a 3.5" floppy?) through 1/2" magtape and C10 cassettes to TK50s, DLT-IVs and 200GB LTO Ultrium-IIs. The microcomputer section included an Altair 8800B, some S100 cards, Motorola MK6800D2, KIM-1, Scrumpi (an SC/MP kit), PET (running moonlander), Apple ][ (displaying a rolling demo of digitised pics), a BBC micro running games and with no less than 4 second processors, an untidy heap[1] of "lots of micros from the late 70s and early 80s", an Apple Mac (supposedly running Pagemaker 1.0 but that was the Mac that got ill) with a modified "1984" promo video[2] at the side, an original pristine 5160 PC/XT, an Amiga, and an Acorn Archimedes. [1] the "untidy heap" was to convey the idea of the explosion of micros that appeared around this time, and included -- some with the tops off -- Exidy Sorcerer, Acorn Atom, TRS-80, Sharp MZ80K, Sinclair ZX80, TI99/4, Sinclair ZX81, Jupiter Ace, Sinclair Spectrum, Dragon 32, Vic-20, Acorn Electron, Sinclair Spectrum Plus, Commodore 64, Commodore 128, Sinclair QL, Sony MSX and probably a couple I've forgotten. Altogether, we counted 16 different microprocessors in the display (another pop quiz question the students were supposed to answer). [2] the video is the 2004 version where the runner is wearing an iPod. We wondered (another quiz question: what was the anachronism) how many students would not notice the iPod because they're so common now, but most of them spotted it. What most didn't get without prompting was the question about how that related to the displays on either side -- which were an Acorn ARM Development system and an Archimedes (with an ARM processor). We also asked them what the most common microprocessor is, and a small number thought it was a Pentium (which doesn't even make the top three, actually). The "business and scientific" section covered a longer period, starting with a PDP-8/E (pop quiz: which machine has been through a dishwasher?) with attached ASR33 and which was running the inchworm and basic accumulator test programs, as well as a little routine to punch "HELLO, WORLD!" souveniers on tape (written by one of the staff who'd never seen PDP-8 code before, so he was dead pleased when it worked). Then we had an 11/40 opened up to the gaze of the onlookers (plus the "Ken and Den" photo at the side) and boards from an 11/03, 11/23, and 11/73, followed by a microVAX-II (no room for an 11/780, alas). The final item in that row was a 20-year-old working 11/53 system running an exam marking system under RSX-11M, with a mark-sense reader -- which booted first time and ran without problem all week, demonstrating -- as we hoped and expected -- that things were built to be reliable in those days. The other side of that aisle was mostly RISC-based machines, starting with an early Sparcstation, then the first microSPARC, a Mac Classic (last 68K Mac, first under 1000UKP), then Indigo, Indy and O2 SGI workstations (what machine do you see in Jurassic Park?) running assorted demos and finally a modern mid-range dual-processor Sun server. Note the complete absence of Wintel PCs (apart from the 5160) :-) We managed to relegate them to a corner table of their own, but we did have a full range of motherboards from XT (couldn't find a 5150 in time), through AT, 386, 486, assorted Pentium and AMDs to a big dual-core machine that will finally be put into service on Friday. The last section was sort of unusual odds and ends -- a piece of one of the Crays the Meteorological Office used to use for forecasting, some transputer boards from a Meganode and a Paramid system, a Presence-II neural net processor board (a PCI card designed and built by the Advanced Computer Architectures group at the University), one module make more lights flash, an Origin 200, and some FPGA stuff from CompSci. We also had some pieces of Elliot 803 and English Electric KDF9 along with someone who had actually worked on these systems, and could talk enthusiastically about the novel and innovative aspects of their architectures, but sadly he got called away mid-morning. We all had an interesting and enjoyable day, though some of us are a bit hoarse from running sixteen tour groups through our parts of the exhibition! One of the technicians took lots of photos so I'll see if I can pick some out when I get a set and put them up online somewhere. -- Pete Peter Turnbull Network Manager University of York