24 Feb
2006
24 Feb
'06
9:44 p.m.
On 2/24/06 6:56 PM, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
I also have several .COM files for a PC/XT I'm going to tear apart tonight
that apparently came with it (along with the basic files)
I'll zip up a copy and put it somewhere, if you wish
We've got
all that, I'm looking more for programming guidelines, as we've
got next to nothing in documentation (Perhaps one apple 2 doc for
interfacing with it, and I'd like to use my portfolio to control it,
somehow.)
I suspect this is differnt, but not very, on the BBC version.
It is not hard to trace out the schematics (give a 4000-series databook
:-)). That would tell you what the signals from the computer do.
The driver, at least for the C64 and BBC version, was a machine code
program. I think you got a binary program for the C64 that you called
with SYS. The BBC version was written in assembler (the BBC BASIC
interpreter includes an assembler). It's not commented, but it's fairly
easy to follow (even for a non-programmer like me). Of course it makes
use of the 6522 VIA chip in the Beeb (and it talks to it correctly, via
an OSBYTE call, so you can run it on the 65C02 second processor).
I've got several tons of GWBASIC files from a four floppy disk set, and I'm
going to tear those apart soon.
I wonder if any of those are equivalent to the ones on the BBC disk.
Comparing them might be interesting...
-tony