'Missing' Digital Equipment Corporation
Field Maintenance Print Sets Online


A substantial effort has been put into making the print sets provided by DEC (Digital Equipment Corportation) for the various computers produced by them over their years of operation (1957-1998), for use by collectors, museums, etc in keeping antique DEC computers running.

A large proportion of the print sets produced by DEC over the years are now online, at sites such as BitSavers and Manx, as well as other repositories maintained by individual collectors, etc; Web searches using popular search engines usually turn up manuals and print sets when needed.

However, there is are several flaws in this system, one of which is that DEC often included the print set (FMPS, in DEC jargon) for a sub-system in the print set for a larger system; e.g. a power supply print set might be included as part of the print set for the computer that used it. Often, these larger print sets are scanned as a unit, and the individual sub-systems are not visible to search engines; Web searches for the prints of the sub-system therefore fail.

Other print sets which cannot easily be found via search engines, for reasons which are not entirely clear, although the lack of a consistent naming scheme (they may be called FMPS, or "Engineering Drawings" - another, earlier DEC formal name, or simple "schematics") is clearly part of the problem.

This site is an attempt to rectify that problem. It provides links to system FMPS's which contain the FMPS's of sub-systems which individuals might search for; hopefully, a Web search for that sub-system will lead here, and from here, to the larger FMPS containing the desired FMPS.

Print sets which cannot easily be found via a canonical search engine (this effort used Google, as it's the most popular) are listed below, in alphabetical order of the sub-system's DEC ID.

Tips For Finding Prints

It can be difficult to find prints online, since there is no single search string form which works with all prints. So searching for '"MS11-L" print' does not turn them up even though they are online; '"MS11-L" FMPS', however, does!

The search terms used in this effort were "{item} prints" "{item} prints DEC" (since for some items, "{item} prints" alone turns up many non-DEC-related results which mask out the DEC related ones). Other useful search keywords are 'schematics' and 'drawings'.

If you can find the MP number for the print set (only on the later prints sets, alas), try searching for that ('"MP-12345"' or '"MP-12345" FMPS'). Adding the '-' may, or may not, give the best results - try searching for '"MP-00317" FMPS' and '"MP00317" FMPS' (for the MM11-Y prints) and see what happens!

In short, try all sorts of variants before you give up! In particular, for devices which include an '-' in the name, it might be worth trying both with and without the '-'.

Note: When looking for core memory prints, make sure to look for both "MM11-x" and "MM11-xP"; sometimes the print sets are filed under the "P" (for parity) designation.

Print Lists

Names are shown exactly as given on the prints; there is some variance (e.g. "11/04" versus "PDP11/23"). Interpolations (to make things more comprehensible in some cases) are given in "[]" brackets.

Device FMPS # Containing FMPS Containing FMPS # Comments
BA11-N Mounting Box MP00487 PDP11/23 MP00740
H403 AC Input Box   PDP11/23 MP00740
H7441 Power Supply MP00271 11/04 Engineering Drawings MP00019
H786 Power Supply   PDP11/23 MP00740
KD11-D MP00020 11/04 Engineering Drawings MP00019
KM11 Maintenance Board   PDP-11/05-S, 11/10-S Engineering Drawings  
M7850 Parity Module   11/04 Engineering Drawings MP00019
M8264 No SACK Timeout Module   11/34 Volume 2 MP00082
M9301 UNIBUS Terminator/Bootstrap MP00196 11/04 Engineering Drawings MP00019
ME11-L [8K] 16 Bit Memory]       See under MM11-L; the ME11-L seems to be an MF11-L in a box.
MF11-L [8K] 16 Bit Memory]       See under MM11-L; the MF11-L seems to be a backplane, plus between one and three MM11-L board sets.
MM11-L [8K] 16 Bit Memory]   PDP 1105 [Engineering Drawings]   The board set is called an MM11-L or -LP, depending on whether it has partity; G110+G231+H214 for non-parity, G109+G231+H215+M7529 for parity.
MF11-S [8K] 16 Bit Memory]       See under MM11-L; the MF11-S seems to be a backplane, plus a single MM11-L board set.
MF11-U 16K UNIBUS [Memory]   PDP-11/05-S, 11/10-S Engineering Drawings  
MM11-B 4Kx16 Bit Memory System   11/04 Engineering Drawings MP00019
MM11-C 8Kx16 Bit Memory System   11/04 Engineering Drawings MP00019
MM11-D [16Kx16 Bit Memory System] MP00032 11/34 Volume 2 MP00082
MS11-E MP00021 11/04 Engineering Drawings MP00019

See Also: Miscellaneous Digital Equipment Corporation PDP-11 Information

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Last updated: 18/June/2020