PDP-8 Documentation

PDP-8 Documentation covers Digital Equipment Corporation's maintenance manual for the original PDP-8 (the Straight-8), with the PDF, and lists the other DEC documents for the machine on bitsavers.

PDP-8 Maintenance Manual (F-87)

DEC's PDP-8 Maintenance Manual, publication F-87, dated February 1966 and printed in March 1966. The scan has 350 pages and no text layer.

Contents, as printed:

1. Introduction and description: organisation, functional description, physical description (p. 1-11) and specifications (pp. 1-13 to 1-14).
2. Logical functions: power and panel lock switches, power clearing, manual and programmed operation, interrupt and data break.
3. Processor: timing, major states, registers, KR01 automatic restart (p. 3-37), Type 182 extended arithmetic element, Type 681 data line interface.
4. Core memory: organisation, selectors, inhibit drivers, sense amplifiers, memory control, the current source and Type 708 power supply (pp. 4-12 to 4-13), Type 183 memory extension control, Type 184 memory module and Type 188 parity.
5. Input/output: Teletype 33 ASR and its control, Type 189 analogue-to-digital converter, W103 and R123 modules.
6. Interface: loading and driving rules, programmed transfer and data break interfaces.
7. Installation: site preparation and power requirements.
8. Operation: controls and indicators, operating procedures, the RIM loader and PAL.
9. Maintenance: equipment (Table 9-1), controls (Table 9-2), preventive maintenance (mechanical, power supply, marginal, memory current and sense amplifier checks, pp. 9-4 to 9-13), corrective maintenance (pp. 9-22 to 9-29) and spare parts (Tables 9-9 to 9-11).
10. Engineering drawings: drawing conventions, semiconductor substitution, and schematics of special modules and of the Type 708 power supply (RS-C-708, p. 10-8), G808 control and G809 relay driver.

Appendices: signal origins and the DEC program library.

What it does not contain

The full logic prints of the processor and memory are not in this manual; DEC supplied them with each machine, and bitsavers holds June 1970 copies as separate files. The power supply schematic gives values for the large capacitors but prints no voltage rating for the 35,000 µF banks. Table 9-3 prints the −15 V output's current rating as 15 mA, while a working machine draws 9.7 to 9.9 A from it.

Pages that cite it

• PDP-8: specifications and construction
• PDP-8 Power Supply Restoration: Type 708 description, outputs, capacitor list and checks
• PDP-8 General Maintenance: preventive maintenance, marginal checks, memory adjustments
• PDP-8 Troubleshooting: corrective maintenance and memory troubleshooting

Download: PDP-8 Maintenance Manual (F-87, 1966).pdf

Other documents on bitsavers

Bitsavers' PDP-8 directory also holds the PDP-8 Users Handbook (F-85, May 1966) with a change notice, the PDP-8 Interface Manual (F-831F, May 1965), the 1965 brochure and 1967 price list, a course workbook, the processor and memory schematics (June 1970), and manuals for options such as the 34D display, AX08 laboratory peripheral, DP01 data channel and RM08 drum.