16 Mar
2004
16 Mar
'04
3:05 p.m.
Jay West wrote:
The 105xxx instruction calls microcode routines, where
xxx represents the
"address" (bits 8-0, 0-1777). However, I don't think the
"address"
corresponds directly to a given word address of microcode. At least on the
21MX it doesn't.
105000 through 105377. You only get 7 bits to play with. And only bits
7-4 are used as bits 3-0 of the microcode ROM address.
The lowest-numbered microcode ROM module, excluding module 0, is where
the primary jump table lives (in the first 16 words).
Is that what you're looking for?
Yes, I oughta get around to post-processing the scans into a PDF.
-Frank McConnell