PDP-8/E and PDP-8/M Computer Information

The PDP-8/E and PDP-8/M were similar computers. The 8/E was introduced in 1970 and had a linear power supply and room for 20 cards including the slots used by the processor. It sold for $6,500. The 8/M and 8/F were introduced in 1972. The M and F only had room for 10 slots and used a switching power supply to reduced the cost of the machine. They used the same cards as the 8/E. The 8/M was an OEM version of the 8/F for people who resold it as part of a system. The 8/M frequently didn't have the full front panel my unit has. All of these models were discontinued in 1978.

Programming information by Douglas Jones.

These machines used the omnibus which all the cards plugged into. The omnibus has 144 lines, 96 of which are signal lines. If boards needed special connections between them H851 connectors were used on the top of the boards. With external expansion chassis up to 60 cards could be used. These machines were made almost entirely with standard SSI TTL chips except for analog functions such as the core memory drivers. The TI 7400 series and Signetics SP300 series were the most commonly used chips.

PDP-8/E Specifications
Word size 12 bits
Maximum memory 32k words (8 4k banks)
Minimum instruction time 1.2 microseconds
Add memory to accumulator 2.6 microseconds
12 x 12 multiply with 24 bit result  256.5 microseconds (subroutine)
12 x 12 multiply with 24 bit result  40 microseconds (with EAE option)
Operating Environment 0 to 55 C (32-130F)   10% to 90% Humidity
Power <= 450 watts (varies with option cards)
Size (HeightxWidthxDepth)  10.5x19x24 inches
Weight 100 lbs total, 45 lbs power supply
Cost Minimum Configuration 4k memory $4490 installation included from DEC in 1974
  $53 per month for maintenance
Cost in configuration shown, excluding I/O devices
and third party boards
$14835 from DEC in 1974
  $134 per month for maintenance

Documents related to PDP-8/E & PDP-8/M

Option cards installed in PDP-8/E

Videos of operation of PDP-8/E. How to view The large realvideo files are the best but slow to download. The large MPEG has some artifacts from being recorded with interlaced video from a camcorder and is larger than the realvideo.

Booting PDP-8/E From RK05. This is the smallest bootstrap for any device, only 2 instructions. The TD8E DECtape is 27 instructions, paper tape (RIM) loader16.
Realvideo: large () Small not available yet.
MPEG: MPEG not available yet.