ard at p850ug1.demon.co.uk (Tony Duell) wrote: That's true for stuff that is built or irreversibly programmed for a particular application, but there were modular systems as well, which could be used for quite a lot of things. The 'process' can often also be scaled for a demonstration model - University has a nice display of a PLC running a model 'production line' built from Fischertechnik: http://www.rt.eei.uni-erlangen.de/FGdes/index_en.html As I happened across process control stuff, some of it inevitably found its way into my collection, namely: -some Simatic N boards (eurocard form factor, DIN connectors) which fit into a small rack and realize simple logic functions like gates and flip-flops (several per card) up to counters and comperators. The person I got them from originally intended to implement some security functions for his model railway with them, reducing the possibility of accidental crashes, but now controls everything by computer. -Simatic C1 trainer set consisting of a piece of DIN top-hat rail mounted on a wooden base and stuffed with "blocks" (functions like the boards; sized like circuit breakers, connectors on the front) together with a 24V supply and a switches/indicators panel, complete with a bunch of wires for setting up the connections. I had that wired up as a 4-bit binary counter when they wanted a prop with lights blinking in a clever fashion for our A-level party. -Simatic S4, microprocessor based PLC (8086 I think?). It is programmed (either with a hand-held LCD device or with a luggable CP/M machine plus the appropriate software and interface)...by designing a Ladder Diagram or "Kontaktplan", a schematic of how you would implement the function you want with relays. The program is then stored in an EEPROM cartridge. I/O is also 24V DC, 230V AC modules were available. I tested it but don't know what to do with it yet; I thought about building a lights and switches panel and implementing a tic-tac-toe engine as a demonstration program. -Sinumerik mate TG, a controller for CNC lathes. This is unfortunately incomplete, since I only have the electronics cabinet, but not the proprietary display unit which also incorporates the character and (I suppose) vector generator circuitry - It was originally there, but was junked before I realized I wanted the thing. I can only hope I'll ever find one again...used replacements are EUR 3000,- upwards. Not much analog stuff here yet, unfortunately - apart frome some chart recorders by HP and Kipp & Zonen (Netherlands). The one HP is a two-channel recorder with fine hoses for ink distribution to the pens and rubber balls for priming - What do the cartridges look for those like? Can you still get them? (It came without.) The other HP is an analog x/y and x/t plotter with plugin slots for pre-amplifier and filter modules. Don't have anything pneumatic or fluidic yet, althought I consider these technologies very interesting. BTW: If somebody has analog control and/or CNC/PLC stuff floating around and wants it gone or swapped, we might try to work something out; I'm located in Germany and will be present at the VCFe 8.0, 28./29.04. in Munich. Greetings, -- Arno Kletzander Stud. Hilfskraft Informatik Sammlung Erlangen www.iser.uni-erlangen.de "Feel free" - 10 GB Mailbox, 100 FreeSMS/Monat ... Jetzt GMX TopMail testen: www.gmx.net/de/go/mailfooter/topmail-out