Forum Iris & Bulbes

By entry I mean both learn or write to this reminiscence tackle. GS. ProDOS incorporates most to all of the disk learn speedups offered by DOS 3.Three third social gathering enhancements, so it doesn't need to be patched to sped up. DOS 3.Three could also be modified to do different issues, such as use a few more tracks on disk for extra area, relocate itself into the highest 16K of reminiscence on a 64K machine, however again, these were all third social gathering patches, nothing official from Apple. The MMU has varied settings for various kinds of memory including the Special I/O house, user reminiscence, and stacks. MMU multiplexes access to real memory and that i/O house. Should a consumer course of try to entry memory outdoors it's allowed vary, an interrupt will happen preventing (or delaying) the access. Interrupt ReQuests (IRQ's): In actual life when the Lisa's 68000 CPU requests some I/O functionality, it does not anticipate the result instantly, nor does it wait for the end result. For instance, our 6504 floppy emulator really reads/writes sectors in what the 68000 would see as a single cycle.