Booting Mac Plus right from ROM + some games! — #21

Post #21 by techknight

Source Forum	68kMLA
Category	Troubleshooting
Post Date	Sun, 30 Nov 2014 - 00:14
Original URL	https://68kmla.org/bb/threads/booting-mac-plus-right-from-rom-some-games.572/

Post

bigmessowires said:
Too narrow - like it doesn't fit in the 512K's motherboard's ROM sockets? Or there's a clearance problem, and something is bumping into something else?

I was looking at this too. With one extra connection to the CPU, I think it would be possible to make the Flash ROM reprogrammable from within a running system. So then you could alter the contents of the ROM disk, or do other experiments, without having to open up the Mac and pull the chips back out. I've got some parts on order to build one of these, then I'll try this to see if I can make it work.

The one thing that bothers me with hot flashing, you would have to shadow the ROM, no? because if I am not mistaken, there are constant calls in and out of ROM. you would almost need to disable ALL interrupts and calls during the flash, which means video would go bye bye.

I would imagine if you write or re-arrange code while that block is running might cause a freeze/hang and poof done.

any thoughts?