Tue Apr 23 07:36:02 2002
Date: Tue, 23 Apr 2002 06:48:48 -0500 (CDT)
From: Daniel Seagraves <email@example.com>
Are the A and M memory on two seperate boards, or are they the same thing
on two busses?
M and A are on separate buses (on the same board, the whole CPU is on
one board). When writing to an M-memory location, the hardware
conspires to write to the corresponding A-memory location with the same
value. It's a cheap way to imitate a dual-ported memory: write to M
all the time, and you can read from either M or A. Three-operand
microinstructions take an M source and an A source.