Musings about a new Apple ][ Operating System

After having fun with Apple ][ emulators on the weekend (see my dev blog), I got to thinking about writing an operating system for the Apple ][ hardware.

I have always thought that I wouldn't be worthy of the title Uber-geek until I had written my own OS from scratch, and the Apple ][ hardware is delightfully simple.

I want it to be multitasking, although I haven't researched the interrupt options in the 6502 yet. To be pre-emptive the Apple would probably need a thunderclock card or similar.

The memory issue worries me - it may need to be all based around relocateable code and memory handles, like Classic MacOS. One smart (maybe) idea I had was to assume an Apple with loads of ramcard expansion, and then to let each process have nearly all of a 48k/64k page. The code could be fixed, and the scheduler would swap between the pages as well as switching execution point. Of course on a real Apple ][ (as opposed to an emulator) the number of processes would be limited to the number of memory pages you had (A Franklin 500 would be nice!) and processes would be limited to around 40 or 50k.

If anyone has any ideas please post a comment!