Date : Tue, 02 Mar 1999 22:38:53 +0000
From : Tom Lees <tom@...>
Subject: The TUBE, etc.
Well, my emulator has progressed quite well so far (although I haven't done
any graphics emulation yet), and I thought it might be fun to try to emulate
the TUBE (in particular the 6502 second processor, which I found
screen-shots of on The BBC Lives!).
I have some sketchy specs (for the TUBE ULA), got the ROM for the 6502
Second Proc., and integrated what bits I could into my emulator. Now, I can
get to two different stages, depending:-
1. If I set up my emulator to emulate a Master 128, I get as far as:-
Acorn TUBE 6502 64K
BASIC
then it seems to hang (dunno if its to do with IRQs and keyboard input or
what, but I don't even get a prompt). Also, I think the "BASIC^A^A^D" is
printed FROM the host CPU, no the parasite. Do I need a special "TUBE BASIC"
ROM?
2. If I set it up to emulate a standard Model B/OS 1.2, it accesses the TUBE
a couple of times, but seems to ignore it, and I just get the usual "BBC
Computer 32K" messages.
So... my questions are:-
1. Have I done something obvious wrong?
2. Presumably the OS 1.2 doesn't contain complete TUBE support. So what does
(on the Model A and B).
3. Why did it crash? :(
Also, any more specs on the TUBE, and the 6502 Second Processor, or others
would be fully appreciated. I found the Torch Z80 ROMs at TBL, but couldn't
find the support discs I seem to remember you needed.
PS. I did eventually manage to read those 3.5" discs, thanks to everyone who
helped out.
PPS. Anyone who wants a current copy of my emulator can have one - ask by private
email. Its written in C++ for Linux and GII (and will use GGI when I write the
graphics bit). If you're really dedicated, you could look at my code and try
to tell me why the TUBE bit makes it crash :)
--
Tom Lees <tom@... > <tom@... > http://www.lpsg.demon.co.uk/
PGPKey: vvv Fight UK crypto legislation - http://www.stand.org.uk/
finger tom@... ,http://www.lpsg.demon.co.uk/files/tom-pgp-pub.asc
GPGKey: above finger and http://www.lpsg.demon.co.uk/files/tom-gpg-pub.asc