DEC engineering drawing numbers

From Computer History Wiki
Jump to: navigation, search

DEC engineering drawing numbers will usually be of the form Z-AA-bbbb-x-yy, where 'AA' is the 'drawing code' (below), 'bbbb' is the device which the drawing is of, 'x' (a digit) is the 'manufacturing series', and 'yy' is the page number within the drawing set. They are often seen with a preceding single-letter code ('Z' above), which indicates the size of the original drawing (listed below).

Drawing codes

DEC drawing codes, embedded in the drawing numbers of DEC engineering drawings, allow one to discern what kind of information is conveyed in that particular drawing. The list of drawing codes, as of circa 1964, was:

Code Meaning
AD Assembly Drawing
AR Arrangement Drawing
BD Functional Block Diagram
BS Block Schematic
CD Cable Diagram
CL Cable List
CP Component List
CS Circuit Schematic
DL Diode List
FD Flow Diagram
IC Interface Cabling Diagram
LO Layout Drawing
ML Module List
MU Module Utilization Drawing
PL Parts List
RL Replacement List
RS Replacement Schematic
SD Specification Drawing
TL Terminator List
TD Timing Diagram
UA Unit Assembly
WD Wiring Diagram
WL Wiring List

Additional drawing codes, seen in later print sets, and their apparent meaning (where possible), are:

Code Meaning
AH Assembly Hole Layout
AL Accessory List
CO Co-ordinate Hole Location List
DC Decal ?
DD Drawing Directory
EC Etch Cut
IA  ? Assembly?
IS  ? Specification?
MD Module ?
MH Module ECO History
PS Parts ?
SP Specification? Procedure?
TC Table of Contents
UA Unit? Assembly?
WT Wiring ?

Drawing sizes

Drawings are usually reduced to 11"x17" (A3, in contemporary paper sizes) for inclusion in print sets sent to customers. The list of drawing size codes for the originals, as of circa 1962, was:

Code Size
A 8-1/2" x 11"
B 11" x 17" (twice 'A')
C 17" x 22" (twice 'B')
D 22" x 34" (twice 'C')
E Larger than 'D' (most are 30" x 42")

See also