Beeb

Emulator:  Beeb
Author(s): James Bonfield (jkb@mrc-molecular-biology.cambridge.ac.uk) and 
           Steve Youell (8271 emulation) (wgc-e@rx.xerox.com)
Platform:  Unix, with or without X11
Language:  C
Implementation (core emulator):

Currently has good 6502 and reasonable 6522 support. The keyboard is
handled correctly by generating the necessary 6522 interrupts and letting
the "hardware" do the work. Graphics support is dodgy. Sideways RAM and
ROMS work fine too. I have minimal 6845 support, but this currently does
work for modes 0, 1 and 2. It even provides some semblance of hardware
scrolling (but only in the Y direction). I'll rewrite the 6845 again from
scratch though as I've got better ideas now which should allow for split
screen modes. 
 
Implementation (8271 emulation):

The idea is to emulate the 8271 rather than OSWORD &7F as in effect all
OSWORD &7F does is to give the 8271 all the data in the argument block.
There will also be the Disk Box which is an X program for selecting disks
and giving them to the drive. It's quite easy really, I don't have to
worry about particularly tight programming as anything I write will be
faster than the beeb disk drive. The idea is to have a program on the beeb
which will take a disk and make an image from it containing all the sector
id's and data. The final goal which would truly show off the beeb emulator
and the disk drive I am writing would be to be able to have a disk image
of exile, to be able to load it, protection 'n' all and then for the
emulator to run it. [SY]