When I got my first Mac Plus I had no external floppy or harddisk, but I did have a PC and a copy of Lightspeed C3.0
Back then I wrote two storage drivers...
1. a serial floppy, using the serial driver I wrote a storage driver that would talk RS232 to the PC. The PC ran a server program that let the mac read, format and write to the IBM PC's floppy. So presumably I was the only person using Mac formatted 720k 5.25" floppies.
2. a RAM disk, the mac plus had 4Mb so I allocated a meg to the RAM disk to put the C compiler. When I started the machine, the first thing I did was copied the C compiler to the RAM disk. I'm sure there were other RAM disk programs available but this was long before the internet took hold.
From memory the storage driver only had to support synchronous operation, not async, which was a real blessing.
Regarding original Mac expansion, that's what the Zilog SCC was for!
Back then I wrote two storage drivers...
1. a serial floppy, using the serial driver I wrote a storage driver that would talk RS232 to the PC. The PC ran a server program that let the mac read, format and write to the IBM PC's floppy. So presumably I was the only person using Mac formatted 720k 5.25" floppies.
2. a RAM disk, the mac plus had 4Mb so I allocated a meg to the RAM disk to put the C compiler. When I started the machine, the first thing I did was copied the C compiler to the RAM disk. I'm sure there were other RAM disk programs available but this was long before the internet took hold.
From memory the storage driver only had to support synchronous operation, not async, which was a real blessing.
Regarding original Mac expansion, that's what the Zilog SCC was for!