What are the really unusual or weird computers?

[Tony Duell]

> 
> On 27 Jun 2007 at 20:17, Jim Leonard wrote:
> 
> > Could you elaborate?  I've never found a single program that will work 
> > on, say, my 5150 but not my 5155 or 5160...
> 
> Including ROM BASIC that writes and reads cassette tapes?

ROM BASIC is present on the PC, XT/Portanble and AT at least. I have no 
idea if it was fitted to any PS/2 machines.

IIRC, cassette I/O went via a software interrupt (INT 15????). The 
routines in later BIOSes (XT, AT, etc) returned without doing anything, 
bnt since all said BIOSes supported extension ROMs, I see no good reason 
why you couldn't have a BIOS extension and a little hardware to add 
cassette I/O to the later machines, if you were insane enough to want it.

-tony