24 Sep
2001
24 Sep
'01
11:42 a.m.
On Mon, Sep 24, 2001 at 11:56:30AM -0700, Chris Kennedy wrote:
Faced with the issue of _how_ to read the microcode
the MV designers
did something modestly clever. Since the MV is an almost-proper superset
of the Nova, and since the Nova ISA was well understood, when a MV first
powers up it thinks it's a slightly brain damaged Nova 800 (there's no
page zero auto inc/auto dec instructions and most "do nothing" I/O an
skip instructions are not honored), which gave them a reasonably
complex abstraction upon which to open and traverse file systems
looking for the MV microcode...
But where is the microcode for the brain-damaged Nova 800 instruction set
stored, and can it be overwritten?
-- Derek