Digital Equipment Corporation Trademarks

Part of the PDP-8 Collection
by Douglas W. Jones
THE UNIVERSITY OF IOWA Department of Computer Science

The Digital Equipment Corporation trademark has evolved over the years. Here is the trademark, as it appeared on company stationary in 1962; this version (and the date) was scanned in from a letter accompanying the press release kit for the DEC PDP-4 computer:

an image, |d|i|g|i|t|a|l|

In the early 1960's, some DEC products even used this logo with alternate letters done in red and blue, but DEC quickly abandoned the multicolor version of this trademark, modified the proportions, and added white space between the blocks, as follows:

an image, |d|i|g|i|t|a|l|

The above version of the |d|i|g|i|t|a|l| logo was scanned from a 1967 vintage PDP-8 pocket reference card.

Some old-timers have suggested that the |d|i|g|i|t|a|l| logo was originally designed to reflect the proportions of DEC's original family of logic laboratory modules. These had rectangular black faces with approximately the proportions of the rectangles in the original logo, as shown in the following illustration:

a drawing of a lab module and a system module

Dec's original System Module family of logic, shown on the lower right in the above illustration, were packaged for individual sale under a plastic bubble glued to a cardboard backing. The above illustration was printed on the back, along with promotional text. The vertical DEC logo was also introduced at this time. The following version of this logo was scanned from the lower front of the same System Module package:

DEC System Building Blocks logo

Digital Equipment Corporation was forced to abandon the use of the three-letter DEC trademark in the early 1960's, apparently because of conflicts with a manufacturer of dairy equipment. At about the same time, DEC changed its System Modules packaging from cardboard backed bubble packs to vinyl pouches sealed closed with a sticker bearing the following artwork:

hexagon |d|i|g|i|t|a|l| System Module logo

The vinyl pouch had the same artwork running down the right side of the package, minus the hexagon. On the vinyl, this was printed as a white band with the dark elements remaining transparent.

This is the only example I've found where DEC used the hexagon symbol in its corporate artwork; this hexagon may be a schematic representation of the same oscilloscope display that forms the basis of the hexagonal DECUS logo, but if so, it has been rotated 30 degrees from its natural orientation.

The preferred color was initially a dark blue-green, as shown in the PDP-8 pocket reference card. Variations on color were apparently used across many DEC product lines; but in the later 1960's, a system of color codes was introduced to distinguish the different product lines. The original color code used for the PDP-8 product line was brown; this was used on the front panel artwork as well as on the DEC logo appearing on PDP-8 documentation:

an image, |d|i|g|i|t|a|l|

The above example was scanned from the 1974 PDP-8 pocket reference card.

In the very late 1960's or early 1970's, DEC adopted a new bold color scheme for each product line. in this scheme, the PDP-8 used burnt orange contrasted with goldenrod on the front panel, with the DEC logo on documentation presented in burnt orange. For the PDP-11, the corresponding colors were maroon and orange. Later, in the VAX dominated era of the late 1970's and the 1980's, DEC abandoned this scheme and went to a blue and white scheme. It is noteworthy that "Digital Blue" was not the same shade of blue as was used in the old PDP-10 color scheme.

In 1985, DEC changed to a grey and white scheme, with the |d|i|g|i|t|a|l| logo appearing in white on a grey band.

This version of the logo was adopted in 1993 and remained in use until DEC was purchased by Compaq:

an image, |d|i|g|i|t|a|l|

This shade of burgundy harks back to the shade of maroon used with the PDP-11 family in the early 1970's, but it appears that the consultants who chose this color scheme, Sampson Tyrrell and company of London, were unaware of this earlier usage. The letter forms used in this logo differ slightly from those used on older versions of the logo. The serif has been removed from the tail of the A, the letters are a bit taller and narrower, and the dot on the letter i is no-longer square.

The trademark PDP stands for Programmable Data Processor. This was used by DEC in various ways through the years. For example, the following style was apparently used only on programmer's documentation produced in the 1960's.

an image, PDP over a big fat 8

Green was the preferred color during the period when the above logo was in use. The shade of green used varied; the PDP-8 logo here is in the color used on the 5/65 pocket reference card, while the green |d|i|g|i|t|a|l| logo shown earlier is in the colors used on the 4/67 reference card.

The following style was used in the 1970's on all manner of material, from front panels to manuals:

an image, pdp8 with the letters run together

This particular example comes from DEC's 1974 pocket reference card for the PDP-8/E. Similar lettering was used on many other DEC products sold during the 1970's. The above logo came into use during the PDP-8 brown era, and remained in use through the end of the orange era.

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