TI 58/59 ROM modules and OP instructions

[Dieter]

(12-30-2017 03:34 PM)Gene Wrote:  I don't know, but if there is an answer, it should lie in the PDF copies of the TI PPC Notes through their 14 year history.

What? You don't have these PDF copies? They can be found here:

TI PPC Notes

Indeed I found something that may be related to the original question. The following is a quote from Volume 4 No. 1 (January 1979):

Quote:A CROM Op Ind
Dave Leising (890) has found an ML-19 point (SBR 172) to execute an effective Op*53, making it possible to have any of the 40 Op functions executed in the CROM.

Lines 172 and 173 of ML-19 hold the codes 84 and 53 which will be executed as OP IND 53. The quote seems to imply that OP instructions usually can not be used in "CROMs" (i.e. TI ROM modules). So this seems to be a known fact as of January 1979. Let's see if some more info can be found in earlier issues.

Dieter