> On many of the PDP-11s that page is signified by asserting BBS7 QBUS machines only; the UNIBUS has no equivalent signal. > FYI the microPDP-11/53 is the 11/23+ cpu card Err, no; according to the "MicroPDP11/53 System Supplement Manual" (AZ-GPTAA-MC), pg. 3-1, the CPU card in the /53 is the KDJ11-D. The /23+ uses the KDF11-B CPU card. Noel