newbie building a scratch-built computer

On 7/30/07, Joe Giliberti <starbase89 at gmail.com> wrote: Hi, Joe, I have looked at the Micro-KIM and think it's a really neat kit. I don't have one yet, but I'll be ordering a bare board as soon as Vince has filled all of the full-kit orders. If you are going to build any kit, ensure you have a reasonable-quality soldering iron. I used to built kits in High School with a cheap Radio Shack soldering iron, and it shows in the inferior workmanship. At my first college job, I was adding ECO (blue) wires with a Weller temperature-controlled soldering "station" (which went with me when the company closed, and was using last night on a Spare Time Gizmos kit). This soldering iron cost my former employer about $250 in the early 1980s, and it still works! It's worth spending a bit on tools that will last for decades and help you produce good product. Metcals are really nice irons, but I haven't run across the right deal yet. If you go to any Hamfests, you might be able to pick up an old Weller for well under $50. New ones, though, are still expensive. If you are already experienced with soldering, you can skip this step, but you might want to consider picking up some inexpensive Ramsey or similar kits for practice. I still have some of my early examples, and, I gotta say, practice does make perfect. The other thing to consider when building a kit is what you are going to do with it when you are done. A working computer that isn't interesting is going to sit on the shelf, assembled but unloved. If you are interested in the 6502, the MicroKIM is an excellent kit to built - there are lots of books on the 'net from the KIM days, and plenty of example code to get you started. It's one of my favorite processors (I got my start on the Commodore PET). Another processor from those days to consider is the 1802. They are still making them, amazingly enough; and old chips can he had for as little as $5 (though $20 is more common - new ones are closer to $90). Bob Armstrong still has Elf 2000 boards and partial kits, so you'd have to be willing to order the rest of your parts - not necessarily recommended for a first kit. http://www.sparetimegizmos.com/Hardware/Elf2K.htm Besides toggle switches and hex LEDs, if you spend a bit more and can handle soldering an SMT CF connector, the Elf 2000 has a disk board and an operating system. Once you load the OS, you can even play Zork on the Elf 2000, if that sort of thing appeals to you. Personally, while the Mark-8 has its place in history, I think it's not as interesting of a modern kit to build. The processor is limited, software examples sparse, and the original Mark-8, at least, was difficult, from a technical standpoint, to build. It's one that I haven't been eager to tackle, even though I do happen to have an 8008 or two on hand. So... I happen to think a 6502 or 1802 would be most interesting to play with after you've built one, but the Mark-8 has some undeniable nerd factor to it. I'm sure you will find plenty of offers for answers and advice here, no matter what you choose to build. Good luck, -ethan