93

1045 Feb. 7, 1968

Turned off machine for ~2 min to switch
off Ampex CORE 0 so that Phil McKay could work
on it. Restarted at 143.

Note: This morning we have had 4 Core Parity
Errors - all of which were in the Ampex Core.
Locations 375735, 202073, 221565, & 340657.

J. Gleason

2:00 7 Feb 68

Fixed bias supply to A-D speech input.

Phil McKay of Ampex installed [?]
pair on AMPEX #1.

SRR

0033 8 Feb 68

While chasing disk bugs we
found that running chess in a certain region
of AMpex core seemed to drop bit 35
and get parity errors.

To get we did following

R FAILSAFE
R CHESS
* PS

got parity errors all with data = 777777777776
at PMA = 63506, 63514, 63502, 63572
63636, 63630, 63506, 63556, 63504, 63506
63514, 63572, 12766, 63506, 63514, 63572
63572, 63622. (FULL INTERLEAVE]

Replaced B28 + B3, B205, R181
for low order 2 [bits?] of MA for 167
fixed reread problems with 167 in AMpex