[...] I found one of those in a skip (literally!) a few years back, and was allowed to rescue it. Mine came as the CPU box with 32K (I think) core, a lot of I/O cards (or at least I assume that's what they are), a paper tape reader and a somewhat mangled cartridge disk drive (1 fixed platter, one RK05-like cartridge). Alas no manuals. It looks like it could be got to run again, but as I know nothing about it, I've not put any time in on it yet.... I swap between the 2 'modes'. Sometimes I'll get a machine because I know what it is, and because I remember it. The Tandy M4 I bought a couple of weeks ago fits in here - I grew up on a Tandy Model 1, and remember the M4 coming out. I wanted one then, but could never afford it. Now I can, and can run those programs from 80-micro.... But more often I get a machine because I have no idea what it is, but it looks interesting. The P850 (the machine that seriously started me collecting) fits in here. As do the PERQs - I thought it was a 68000 box when I got the first one, and was amazed to see a soft-microcoded CPU. Learning from such a machine is great fun... [...] I certainly grab schematics and printsets without the hardware that goes with them - you never know what will turn up later.... It's not that hard. What started me off was getting a relatively simple minicomputer - I'd recomend either the PDP8/e or the PDP11/05 as a starter, and sitting down with the machine, the technical manual, and the printsets. I single-stepped the machine, and watched how it executed an instruction with a logic probe. I where the microcode went, what gates were enabled, etc, and related it to the diagrams in the manual. After a couple of days I could understand most of the instructions.... Yep... CPU Technical manuals from the late 1960's - early 1970's. Most of those include a gate-level description of the CPU operation. It helps a lot to have the machine in front of you, though. -tony