Building a computer (May or may not be OT)
- I'm not talking about a PC, first off. I want to try building something from scratch, as in a blank, wire-wrap circuit board, based around an earlier technology. Maybe a 6502 or a Z80. Does anyone know of a kit, of a good set of instructions and schematics, for building a computer?
Basically, I'd want a display, and a means of input and storage. I don't care if I use, say, a VGA monitor for display, or an old disk drive for storage, but I want to build the computer itself, myself. I just want to learn something more about computer science, outside of what you can learn on a PC.
- Like many discussion threads, this one is going in several directions.
1) University libaries. People local to a university can often get
limited privledges by paying a deposit, or an annual fee. Check the
library's Web site for more information, or ask a "senior" staffer at
the library (student staff may not know this stuff). University
libraries are good sources for books a few decades old. But you won't
get "interlibrary loan" privledges as a "depositer" at a Univ. library
- but you can do that from your local public library.
2) The microKIM uses a few odd parts, and of course some ROMS. Joe, if
you make one from scratch, better plan on a way to get those ROMS, and
make sure you can get ALL the chips on the schematic. The ROM source
and binaries are available from the microKIM site.
For fun, if you do make a list of parts and prices, I'd be curious to
know the total. Betcha the kit price will be close to your onesie's
parts prices! ;)
3) The microKIM does not normally have a cassette port; programs are
downloaded from the serial port, which one would generally connect to
a PC where you can load and save programs in hex format. Consequently,
using a PC with the microKIM is just fine. But you can of course load
programs in hex from the keypad.
My advice was to program from the keypad, by the way, as a way to
learn coding at the bit level. That seemed to be your interest.
4) Building a TV Typewriter, or the II, will be harder than building
the microKIM from scratch. I'm not sure what your objectives or
priorities are, my apologies.
5) Please read the microKIM manual to get a better idea of what you'll
need to use it. If it's not on the Web site, ask for a copy from the
seller. Chances are he'll send a file, or if he charges for a printed
version he'll deduct it from your kit purchase.
This ends my advice. Joe, you are a good guy, but you want to do many
things for many reasons. That's fine, but it's more than an old guy
like me can keep up with. No disrespect meant.
Herbert R. Johnson, New Jersey USA
http://www.retrotechnology.com/herbs_stuff/ web site
http://www.retrotechnology.net/herbs_stuff/ domain mirror
my email address: hjohnson AAT retrotechnology DOTT com
if no reply, try in a few days: herbjohnson ATT comcast DOTT net
"Herb's Stuff": old Mac, SGI, 8-inch floppy drives
S-100 IMSAI Altair computers, docs, by "Dr. S-100"