SC1041_SAIL_PDP-6_hardware_log_1968-01

0530 1-Mar-68

After some poking it was determined that the "It won't run me!" bug in 3.15/07 was due to the scope hanging up and the system being unable to shuffle a user who had gotten stuck in the middle of core. Thus there was not room for a large user to be brought in. 3.15/08A has a patch whereby the 136 is blasted if it takes too long (length of time is calculated from word count: 1 jiffie per 200 words). The display is seen to flicker badly on occasion but at least it doesn't hang up the system. J. Sauter

127

1700 MAR 1

TTY5 suddenly began mixing up characters. Didn't print character typed or printed wrong character. It had wroked OK for ~ I have previously D. Preper

Mar $ TTY 0 doos not C/R Lou

Mar 4 [underlined] Amplifier mounting for the microphone is falling apart. Need a better mounting Roi Roddy Remounted. J.H.

Mar 4. [underlined] On Feb 28 (pag 124 above) it was noted that TTO has problems. It has NOT been fixed. This TTY is vital to the Hard Eye project and should have a fault high [Dr?] to be fixed [Illegible signature]

1443 4 Mar 68

Ran MAGTST on a short tape for about 2 hours. (6 passes) Got only 4 "compared data not equal" errors in that time. no other errors at all. I am not sure that this error rate is above the noise level. I

I suggest that if there is trouble with the MAG tape a good first aid measure is to clean the tape drive. SRR

0100 5 Mar 68

From spacewar bit 35 [pieces taped on the page]

SRR

0900 5 Mar 68

Space war button 35 switch replaced [Ted Panofsky?]

1020 Have called Jesse Gonzales regarding our current problems on TTY0 and TTY5. He is going to come tonight to repair them. (See Pg. 124 + 127.)

Last night we tried to find the cause of the "hum bars" on the TV monitor. There is ~0.1V of 60~ ripple coming out of the camera. The +20V supply has 0.1V pK-PK ripple on it and the -10V supply has .05V pK-PK

March 5, 1968

ripple. According to the manual both of these supplies should have less than 0.1V pK-PK ripple on them. We tried putting a 100 μfd capacitor across each of these supplies: The ripple on the -10V supply dropped a factor of 2, but the intensity of the hum bars did not change. The ripple on the +20V supply (and the hum bars) were not affected by the 100 μfd capacitor. The "hum bars" are probably produced by the ripple on the +20V supply and we'll have to get a larger filter capacitor to reduce it. J. Gleason

Mar 5, 1968

TTy 5 cleaned Kybod contacts and adjusted Print Suppress Code bar.

TTy0 cleaned Kybod contacts wouldn't CR change station 630 sys and Trouble cleared Jess Gonzales

0125 6 Mar 68

Looked at trouble with line 0 in 630 If you type .SISI to 2.8 it responds with: SISI (hangs) if you type space it responds with ? and hangs with "echo check". Typing Space again clears the "echo check" and CR LF is typed out. It looks as though the trouble is in the 630 transmitter logic, but the trouble went away after a pause and loading 3.15. SRR

0125 6 Mar 68

Also spacewar was having a lot of growing & shrinking of the picture on the type 30 display. SRR

0705 6-Mar-68

Disk turned on "chiller temp. alarm". Suitably scared J. Chowning. I turned off electronics power. DIsk was not running on-line at the time. The thermometers behind the disk read, left to right, 74°, 74°, 74°, 60° (wet bulb), 72°. Chiller was still blowing hot air out its rear vent. Coffin was off. At 0720 the alarm would no longer sound, so left alarm on but electronics off. I have left the disk motors on. John Sauter