pdf has very good page breaks now.
would be a good copy for fall 2009.

IRQ_OFFSET -> T_IRQ0 (a trap number not an IRQ number)
T_SYSCALL 0x30 -> 0x40 (move out of IRQ range)

if no lapic available, use 8253pit for clock
now xv6 runs both on qemu (uniprocessor) and bochs (uniprocessor and MP)

don't use the same name for two different pieces of code

ioapic

Undo change from this morning that wasn't intended to get in.

disk interrupts (assuming bochs has a bug)

and plan 9 code, at least boots and gets into C code.