The 11/34 powered the Schlumberger wireline logging units in the offshore Gulf of Mexico, beginning in about 1980. Schlumberger designed dozens of Unibus cards,

The 11/34 powered the Schlumberger wireline logging units in the offshore Gulf of Mexico, beginning in about 1980. Schlumberger designed dozens of Unibus cards, one as a controller for each logging tool. So most of the system was a giant slotted cage for sliding the appropriate cards for the job, into. The main peripherals were a TI thermal printer and keyboard, a tape drive, a Tektronix display, and a continuous film recorder unit that captured the scrolling Tektronix image. I found this image: http://2.bp.blogspot.com/-O6FC-DLQI5w/ThWTeDxv2-I/AAAAAAAAB2E/3C7XrbFekp8/s1600/Logging_unit.jpg http://2.bp.blogspot.com/-O6FC-DLQI5w/ThWTeDxv2-I/AAAAAAAAB2... The PDPs are lower left; behind the panel directly in front of the engineer is a whole mess of Unibus cards. The most amazing thing about the system might be the number of cards you could plug into it. Edit to add: The plugin cards were way more than controllers. They were (analog) computers too, fulfilling signal processing functions, and other computations, the poor little PDP could not hope to keep up with. For example, one device detected, I presume using analog circuitry, the peak of the first arrival of a sound wave transmitted through earth and mud, across a couple of meters. The card would report the time between the click and the peak of that arrival, back to the PDP. Nowadays you'd digitize the signal and write a program to look for the peak. Back then you designed circuits!