looking for 2100S microcode programming snippet

From: Frank McConnell <fmc_at_reanimators.org>
Date: Tue Mar 16 23:05:06 2004

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
Received on Tue Mar 16 2004 - 23:05:06 GMT