> i had an idea a few weeks ago to toggle the a20 gate on a 286, and use the
> memory from ffff:0000 to ffff:ffff for a ramdisk. this way we could use
> 64k-1byte of memory, which would otherwise be wasted.
8086 doesn't have A20 line ?! It might actually be more useful to find
out what would be required to switch processor into protected mode
(286). This way we'd have 16 MB of addressable memory. If my
understanding is correct bcc wouldn't need any modifications in order to
produce pmode binaries, segment limits are still there, task switching
mechanism would still work (because of same CS and DS limitations).
The problem is that i don't really understand that pmode example on
www.x86.org .. it's weird. The only person that seemed to have a clue
about 286pmode dissapeared without producing any usable results.
Maybe Alan Cox will have some time eventually to explain what needs to
be changed in order to switch to pmode (memory allocation, interrupt
handling and kicking out BIOS drivers i presume).
bye, Ab
