I don't know if he saw my message here or on alt.sys.pdp11, but I have just been sent (from the latest edition 11/24 tech manual) the relevant parts of Appendix D, "PDP-11/24 CPU Modifications". These three pages explain the "Value Engineering" (replacement of logic with gate array chips) redesign of the M7133 -YA version. Most importantly they contain the new switch/jumper settings and location. Thanks Ed! -Charles