Motorola 68010

processor A microprocessor from Motorola. It was the

successor to the Motorola 68000 and was followed by the

Motorola 68020. Some instructions which were previously

user mode were made system mode, which necessitated

patches to a few programs.

The 68010's main advantage over the 68000 was that it could

recover from a bus fault. The 68000 microcode didn't save

enough state to restart all instructions; the 68010 corrected

this fault. This allowed it to use paged virtual memory.

The 68010's DBxx (decrement and branch) instructions could

hold and execute the preceding instruction in the prefetchbuffer, allowing some two-instruction loops to execute

without refetching instructions.

At one time there was a 68010 variant that was pin-for-pin

compatible with the 68000. Early Amiga hackers replaced

their 68000s with 68010s in order to get a small performance

increase.

(1995-11-29)