I missed the start of this thread, however if the trick is to build a microcomputer from scratch then I can suggest two possibilities: 1) Build it around a '5 chip' computer. Z80, Z80-CTC, 2816 EEPROM, 6116 2K RAM, Z80-DART You will need to add a 2Mhz TTL "can" oscillator a MAX233 TTL->RS232 signal level converter a 5volt regulator I can supply you with a nice 2K monitor that I wrote for the Z80 that lets you dump memory, enter hex into ram, and basically have a good time with it. (I've got both a 2K version and a moderately more sophisticated 4K version) 2) Build it around the Motorola 68HC11 single chip processor The MC68HC11-E2 has 2K of flash on board and 256 bytes of RAM. Just add an RS-232 level shifter and 5 volts and you are done. Search for 'BOTBoard' to find a _really_ easy to build system. PolyPaks was famous for this. It wasn't until much later that I figured out _why_ they were so cheap. I ended up buying one of those "assortment in bins" thing for $100 (huge budget on my part!) and had a great time with a DigiDesigner building and using circuits. Gear acquistion plan: #1 Soldering iron (from this you can make a continuity tester with a lightbulb and two clips) #2 Digital Multi-meter (Volts/Ohms/Amps at least AC and DC scales) (these are now dirt cheap thanks to single chip solutions) #3 Now build a logic probe, have it capture high/low and clock signals. Next build a simple TTL level input frequency counter. #4 on my must have list is a decent power supply, you can build one from a kit or buy one, don't skimp, get at least 5v, preferably three supplys (two adjustable) to be able to do split supply things #5 on my "must have" then is an oscilloscope. 20Mhz bandwidth is fine for early TTL stuff, but you'll probably want to end up with a 100Mhz or better scope. #6 build an Eprom programmer (for micro processor development) it is easy to build one for a single family of Eprom. Even easier if you target EEPROMs (no UV eraser needed) #7 is a function generator. If you are going to diagnose things you have to know you are starting with a valid signal. This is also invaluable when doing analysis of AC circuits. #8 is a logic analyzer or state analyzer.Once you go to far down the sequential logic path you will need one of these (Tony: Did you know Agilent has discontinued the LogicDart!?!?) #9 Get a x86 architecture machine for your bench. You'll probably run DOS on it (maybe Windows) so that you can run the free tools that manufacturers give away. #10 Schematic Capture/PCB Layout package (run it on your PC from step #9) there are some reasonable ones that are cheap (EZTrax is free for example) At this point you are equipped to build what ever you need next... --Chuck