SC1041_SAIL_PDP-6_hardware_log_1967-04

2100 17 Sep 67 Put mod 33 on as console TTY REMOTE , LOCAL , POWER ON lights on 545 [strikethru]are [bar?] of burned[/strikethru] do not light. [initialed][SRR?][/initialed]

0045 18 Sep 67 Pluged in MEM Bus for DISPLAY PROCESSOR. Had to unplug and replug every memory buss cable and almost every 1664 and 1665.

0235 18 Sep 67 Going Home. Machine is DOWN There are [R?] problems.

a) if bits 19 and 21 are on in a deposit bit 20 go on between CP and parity box

b) bit 20 can't be written into core 2 or core 3

c) Something is in the fan in core 2 Machine is de-interleaved, PDP-6 mode [initialed][SRR?][/initialed]

[page]149[/page] 18 Sept. '67 1130 DP mem. bus (P3) debugged (?) CP IS NOW ON P3!! DP can go on P2 Removed incorrect jumper on 6227's in all memories; they were making P2 LAST always true. DEC LOSES. [initialed]D.P. and P.P.[/initialed]

20-Sept 67 Repair model 35 teletype line feed stripper slide pin and spring off due to retaining ring breaking. worn rocker extension will replace 9-22-67 TTy will work now [initialed]Jess [Gonzales?][/initialed]

21 Sept. '17 1700 EXAMINE with machine running apparently killed machine. [initialed]D. Poole[/initialed]

1800 21 Sep 67

Had several many DECTAPE errors in system EMERGENCY MAINT DECLARED at 1245

Found several tapes that tested bad. One was an old scratch tape. Another was a newer scratch tape. Rewriting Block marks on this tape gave 2 errors only. Rewriting them again made the tape work test OK. Another was a new tape that had just been opened. Tried a new tape. It tested OK.

Conclusion: (pick 1)

a. Merely by coincidence several bad tapes including one new one had a random error that went away.

b. There is an intermittent in the Dectape controler that disappeared about 1600, but will return at some suitably embarrasing times.

I favor conclusion b.

Machine back at 1800 SRR

22 Sept 1800

TTY7 substitutes rubout for many other characters notably altmode.

Puigle

1000 22 Sep

Tested dectapes. Found an old scratch tape that got random errors on drive 3. Errors were reported by EXDATA and consisted of dropping a 3-bit frame from the record. Location on tape moved around. Tried replacing the timing track reader and the PA's + [inverters?]] in the tuning chain. Also the mark track window decoder. No change was found.

Tape work fine on drive 7 which was the newer leads and is not worn as badly.

I suspect that the heads on Drives 2 and 3 are worn excessively, causing skew problems.

SRR

1910 22 Sep 67

TTY2 reciever picks up but to make [?] into RUBOUT.

Replacement has flag permanently on/ Do not use 630 line #2 SRR

Sept 22 67 Returned TTy Ser #34466 completed overhaul of all model 33 TTys Replaced worn rocker shaft extension on model 35.

Jesse Gonzales

0100 9-24-67 Green Monster is sick. Relay sensor switch can't make up its mind. Machine is now on fan only (no cooling)

B.P.

2152 29 Sep 67 1) Replaced 4706 for TTY line 2. It works.

2) Temperature was up to 75°. Turned on - - - Green monster. It mad bad noises. I removed the cover on the lower section and found the big motor control relay chattering. it stopped and wouldn't do it again.

3) Put MOD 35 on Console TTY and mod 33 on as TTY 2.

ARR

24 Sep LLC CARDS IN 167 NOW HAVE -10V DC SUPPLY + SENSE LINK HOOKED-UP

Randy