108

Dec. 1 10.40

Printer skip lines P.J.V.

1245 30 Nov 67

System kept dieing with NON-EX MEM.
Took [marline?] for Emergency maintenance.
BLT stopped at [1?3] claiming 000's were
storing wrong effective address.
Bit 35 of PMA is out. → Russell was conused
MI Bit 11 is out.

Reason BLT wouldn't run was failure
to put machine in PDP-6 MODE

Ran BLT some more. Occasionally it
hung up Bit 25 in the PC was observed
to be on.

Tried swapping 6206 for MA & PC bit
25 with 6206 for Bit 18. Got non ex mem's
with a little waiting Bit 18 of PG was on.

Replaced the 6206 in bit 18, formerly
bit 25.

System up at 1800 DOwn for 5 hrs 15 min

Violent Pounding on the N end
of the 6205's for the Right 1/2 [wd?]
causes the machine to stop with
many 1's in MA and a non-ex mem.

SRR