On Tue, 8 Jan 2002, Matthew Dillon wrote:
> :
> :That brings back memories. We wrote our own firmware for the 1541 since
> :the commodore DOS was so slow. I forget what transfer rate we managed but
> :it was much better than the standard code. Bit of a sod to debug though.
> :
> :--
> :Doug Rabson Mail: [EMAIL PROTECTED]
> : Phone: +44 20 8348 6160
>
> Yup. Remember Bryce's 1541 Flash? He was working on beefing up
> the C64 serial link while I was working on beefing up the PET's
> (software driven) IEEE-488 link. We both managed to increase disk
> bandwidth by an order of magnitude, mainly by synchronizing the
> computer's 6502 with the peripheral's 65xx and then just stuffing
> data into the ports without bothering with any handshakes until the
> very end. That old usenet posting I posted has some references to it.
I wasn't really into the C64 scene (it cost significant money just to get
Usenet access in the UK in those days). I was working on a C64 game at the
time and I remember spending many unhappy hours trying to fix some
problems with the drive firmware.
That was a pretty cool project actually. The game was a text adventure
originally written in 68k assembler and we wrote a 68k emulator and VM
system which paged the game's 128k address space from the floppy into the
C64's teaspoonful of memory. All the development was done on a Microvax
running 4.2BSD. The vax generated C64 disk images which we downloaded via
the C64's serial port. Those were the days <sigh>.
--
Doug Rabson Mail: [EMAIL PROTECTED]
Phone: +44 20 8348 6160
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