Stupid lusers...

From: Ethan Dicks <erd_at_infinet.com>
Date: Sat Jun 6 17:10:58 1998

>
> I just ordered a 68010 for my Amiga 1000 from a collector and recycler
> of Amiga parts. I was told the main speed increase would be in memory
> intensive operations.
>
> James

There is a one-instruction pipeline/cache that allows memory copying
loops to execute significantly faster. If you want to copy a buffer
to a single word (output port), or move hunks of memory, _and_ you
can express it in a single MOV/DBcc pair of instructions, you get the
win.

Other than that, the big benfit of the 68010 are useless to AmigaDOS -
instruction restart (needed for reasonable implementations of VM). There
was a UNIX box, made by Perkin-Elmer that had two 68000 processors
coupled to implement page faulting. When the main processor would fault,
the secondary would load the desired page into RAM and restart the
primary at the new page. Ugly. That's why Sun used the 68010 early on.
You access non-existent memory, get a page-fault trap, your kernel
figures out where to put the wanted memory and returns from the trap.
Your code never knows that milliseconds have elapsed.

-ethan
Received on Sat Jun 06 1998 - 17:10:58 BST