On 7/10/18 2:38 PM, Noel Chiappa via cctalk wrote:
There is mention in the J-11 specification documents stating 11/70 and 11/44 features were the target. The force miss CCR bits are present in both, to allow for segregation of the cache(s). Thus the compatibility may span both. Interesting to note that if there were feature conflicts, these where solved in favor of the 11/44 except for special cases.> From: Jerry Weiss> See http://simh.trailing-edge.com/semi/j11.html for information on the > design of the J11. Thanks for that pointer; I don't think I've ever seen that - quite interesting. Alas, it didn't have the cache info - but now that I've though about it overnight, I'm pretty sure the reason for the two bits that do the same thing is for -11/70 compatability.
You can find copies in http://bitsavers.informatik.uni-stuttgart.de/pdf/dec/pdp11/j11
Jerry
