PDP-11/20 Exhibit - Videos

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Front Panel operation

The PDP 11/20, like many minicomputers of the 60's and 70's, had a "front panel" called a console which was used to access the computer and program it at the binary (bit) level, one memory location and one instruction at a time. Our 11/20 console is described in detail on the PDP-11 Web page.

Mouse-click the image for a video of the operation of a DEC PDP-8 console. The PDP-8 is a smaller "cousin" of the PDP-11, similar in age and function but which runs different software. The video shows the operation of that console, in a manner similar to the 11/20's console, to start up the computer. Here's a text description of the front-panel operations in the video.

the Teletype

It was common to operate PDP 11's with a Model ASR-33 Teletype. This was a person-operated printing terminal with keyboard, which could also read and produce paper tapes. The keyboard could also be used to create tapes with ASCII text information, or ASCII paper tapes could have their contents printed at the terminal.

Teletype session with PDP-8

Complete operation of a Teletype with a minicomputer is shown in this 3-minute video. Mouse-click the image at the left for the video. Additional videos as below, will show details of the Teletype's functions. The operator uses the Teletype's keyboard, printer, tape punch and tape reader to interact with a PDP-8, an older DEC computer than the PDP-11/20. The operations shown are similar to those with the 11/20 with the same Teletype. A detailed description of the user's operations in this video is in the linked text file.

Teletype: print text, read and write punched tape

The Teletype prints text, either as received from the serial line, or "echoed" from the keyboard, or from ASCII text read from the paper tape reader. Here is a video of the printer in operation. Mouse-click the image at the left for the video. The text printed on the Teletype is a FORTRAN program.

The model 33 Teletype can also punch a paper tape with an ACSCI or binary pattern of eight bits at a time. Here is a 2Mb .AVI video of the Teletype punching a tape. Mouse-click the image at the left for the video.

The model 33 can "read" the paper tapes it punches. Here is a video of the reader in operation. Mouse-click the image at the left for the video.

Production of these videos was by David Gesswein of pdp8online.com PDP-11/20 exhibit developed for MARCH by Herb Johnson. Updated Dec 5 2008.