PDP-11/45 RSTS/E boot problem

Fritz Mueller fritzm at fritzm.org
Sun Dec 30 19:55:22 CST 2018

Hi all,

Some here may know I’ve been working on an 11/45 restoration off and on for some time now. My ’45 currently has floating point, KT11-C mem mgmt, 124 kword MS11-L, and an RK11-C with one restored RK05 drive.

Last week I decided to see if I could bring up RSTS/E on the machine. I managed to sysgen a minimal V06C system that can run off a single RK05 pack under simh, but when I transfer that image to the real hardware using pdp11gui it does not seem to completely/successfully boot.

The “Option:” boot loader comes up and sub-commands there seem to be working (in particular, the “HARDWARE” sub command shows correctly detected hardware and options). When booting RSTS/E, after supplying date and time, the idle pattern starts on the front panel (but just the bottom part, on the data lights). When console is in display register mode, it shows an increasing count. Console input is echo’d, but the INIT banner and subsequent prompts are never printed and the read light on the RK05 flickers continuously as if the system is trying to read the same sector over and over.

Figured I’d ping here in case this is a known failure mode to folks more familiar with RSTS/E? Also posted over on the vcfed DEC forum.  FWIW, the machine is passing all MAINDEC CPU, MMU, FP, KW11, and RK11 diagnostics.


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