the stigmata of IBM feces

[Gordon JC Pearce]

Roger Merchberger wrote:

> I just stumbled across some boards I'd stowed from some older IBM 
> cash-register machines -- I can figure out some of the major chips 
> (EPROMS, RAM, some of the CPUs, etc.) but other than that, they're 
> pointless to me and I'm getting ready to dump 'em; no good to me if I 
> can't even part 'em out to make something kewl...

What model of IBM cash register?  There is a lot of hardware 
documentation available online.  All bar the very early kit is mutatis 
mutandis a PC, with a special ASIC that controls the POS equipment.  You 
can even buy an expansion card with an adaptor box and IO strip to drop 
into a PC and control POS devices.  It's just the ASIC and some glue logic.

If you've got the model numbers, that would be a great help.  IIRC 4683s 
are based on 286s.  Master tills have a 286 CPU, slave tills are 
effectively just a dumb serial terminal.  I don't know what's inside the 
4693, but suspect it's at best a low-end 486, and 4694/4695 and up are, 
as I say, just plain old PCs.  I've booted Linux on a 4695, to the 
amazement of one of the level 2 techies at work.  Just plain ordinary 
tomsrtbt...

Gordon.