Re: HELP: Blueprints for a Computer

[Rubywand <rubywand@swbell.net>]

Dave Ventura <ventudg@yahoo.com> writes ...


> Hello. I would like to build a primitive computer as a hobby. Somewhere
> along the technology lines of an Apple I or II, IBM AT, VIC-20, etc..  I 
> would like to build it from the ground up (soldering IC chips and 
> what not). After I get it working, I hope to write a command interpreter
> (BASIC-like) for it with grammars. Does anyone know of what kind of 
> resources (physical or digital) I could use as a set of blueprints, or
> kits, or reference. ANYTHING. I am in the dark about this but very excited.
> I would appreciate any and all suggestions.
>
> Thanks in advance to all who appreciate a love of computers and help. 
 ....

     Building a computer from the ground up really is bunches of fun; plus,
naturally, you learn a lot. My start was with a 6502-based KIM-1 my dad brought
home from a company seminar. We added RAM and all sorts of ports, re-wrote the
firmware, burned PROMS, expanded the display, added peripherals, ... .

     KIM, of course, was not "ground up"; it was a very good learning tool,
though. My first from-scratch computer was built around the 8086. Intel gave
out the manual + uP in 1976. This plus goodies from dumpster diving made it
possible to put together a computer for nearly zero cost.

     The most fun is, probably, adding features-- like tape I/O, a video
display, telecom port, ... -- and writing the firmware. As your firmware gets
better, it's easier to improve the firmware-- kind of neat.

     Since you mention Apple II and VIC-20, you may want to think about
building a 65C02 or 65C816 system. These microprocessors are available from
Western Design Center (http://www.wdesignc.com/).

     As has been mentioned, you can find the Apple II+ schematic in the 1979
Apple II Reference Manual. Commodore's Programmer's Reference Guides for the
VIC-20 and C-64 include schematics for those machines.

     A very good collection of 6502 schematics and hardware/software
information is the set of three manuals which came with KIM-1: the User Manual,
Hardware Manual, and Programming Manual. These sometimes turn up in used book
stores.



Rubywand