29 Jun
2007
29 Jun
'07
3:36 p.m.
On 28 Jun 2007 at 23:06, Tony Duell wrote:
You;'ve been on this list long enough to know that I'm often pedantic ;-)
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.
Now you're being pedantic, Tony! i'm not aware of any stock plug-in adapter that gives one 5150-style cassette I/O on a
5160. I might as
Nor am I. I was just saying it's possible, using documented software
interfaces.
well claim that I could run Windows XP on a 5160,
given the right
hardware and software additions.
Oh come on. There's a big difference between writing an extension ROM,
which follows a well-docuemtned pattern, to implement a well-documented
function and replacing the procesosr, memory system (I doubt you'll get
anywhere with XP in 640K), expanding the address bus, replacing the video
system (XP won't run on nn MDA or CGA card), etc, etc, etc.
-tony