Artifact Details


FABRI-TEK Mass Core "Moby" Memory

Catalog Number



Physical object


This memory unit was initially installed on the MIT AI Lab’s DEC PDP-6 computer in about 1967 and was later connected to the Lab's DEC PDP-10 computer (in both cases running ITS), until it was decommissioned in about 1986. It has 256k of 36-bit words (internally, 40-bit words) running at a cycle time of 2.75 μs. It was nicknamed “Moby,” after the whale Moby Dick, since it was considered an enormous amount of memory at the time.

The front panel door contains a control panel , which has several indicator lights, switches, dials and a "Percent of normal gauge". The control panel is divided into four areas labeled, "Address register", "Data register", "power control", and "Test control". On the blue part of the door "Go Check" is handwritten in pen. There is a Mass. Inst. of Tech. (MIT) sticker as well as a sticker reading "PROP. of U.S. GOVT. USN". Taped in the Data register section there is a fortune cookie fortune reading, "A good memory does not equal pale ink." There are another two fortunes taped to the interior of the control panel. One reads, "Vanity plays lurid tricks with our memory". The other reads, "You will hear pleasant words which will remain in your memory". Taped to the lower section of the interior door there is a paper with a matrix regarding quick-latches and cable and pin connections. On the power supply the is a partially filled in table reading "Measure with machine stopped".There are five repair tags from A.I. laboratory. The machines is densely wired and populated with circuit boards of various sizes.


ca. 1967



Identifying Numbers

Model number MT Found on the middle panel on the right of the latch.
Other number 002936 Handwritten on the front of the door.
Other number 79457-1394 MIT div. of sponsored research no. stamped into a metal label on the front of the door.
Other number 969-5077 Found on a peeling sticker on the interior of the front door panel.
Other number 999-5047-00 Customer part number Found on the middle panel on the right of the latch.
Other number MIT-0002936 MIT barcode in the top left coner of the door.
Other number X632.85 Acquisition registration number found on a paper label zip tied to the side of the machine.
Other number XPR45-A1 Part number for the power supply
Serial number _2501 Found on the middle panel on the right of the latch. The number is scratched and difficult to read.


front door panel: 65 in x 20 1/2 in x 1 1/4 in; overall: 69 in x 50 in x 25 in


Memory & storage/core


Gift of Systems Concepts, Inc.

Lot Number