http://www.bigmessowires.com/2014/12/20/rewritable-rom-disk-for-mac-plus/
Stuffing new technology into old hardware is fun. How about a bootable, rewritable ROM disk for a Macintosh Plus, using modern flash memory? Dream no more, the reality is here.Using a small adapter board, the original ROM chips on the Mac’s logic board are replaced with 1 MB of flash ROM. The flash ROM contains a modified copy of the original Apple ROM data plus a special disk driver, and a disk image occupies the remainder of the 1 MB of flash. When powered on, the Mac can be booted from the built-in ROM disk with a single key press. When necessary, the contents of the ROM disk image can be rewritten from within the running system, using a custom-made flash updater program. You can fill the ROM disk with system software and a couple of games, or whatever you want to show off without needing a disk. The same thing should be possible for the Mac 128K and Mac 512K too.![]()