I started the thread after a couple of glasses of wine and had come over all reminiscent
And what a terrific thread it's turned out to be, some fascinating insights, thanks to everyone for sharing.
Not exactly on 6502 topic but somebody mentioned that their early coding was centered around the process of transferring BBC micro games from tape to disc, a process that was often uncharitably described as "software piracy" and one that was very dear to my own heart back in those days.
Well anyway, I thought I'd share my own particular, somewhat radical, breakthrough in this area which served me extremely well from it's "invention", pretty much up until the end of my years of BBC gaming.
Essentially it was centered around the fact that when you pressed the Break key on the Beeb it triggered a 6502 hardware interrupt which essentially paused the entire CPU, and when you released the Break key it triggered a JMP to a particular address in the OS. So what I did was to fit my OS into a ZIF socket ..
I then coded and burnt myself a new OS chip (which I childishly entitled HackOS) that replaced the code at the aforementioned address with code that dumped the entire contents of memory to a bank of "sideways" RAM (I suppose an early "hibernation" file if you will).
With the original OS in place I'd load up the game from tape and get it to the "Press SPACEBAR to play" point, then press and hold Break, pop open the ZIF socket, replace Beeb OS with HackOS, lock the new chip back in and then release the Break key again. The 6502 would jump to my oo code and bingo! complete dump of the in-memory game, all primed and ready to run. Save that to a floppy disc and Bob's yer uncle.
Almost certainly used that to create a
pirate backup copy of Elite.
Ahhhh, happy days
