PDP-12 System Reference Manual

This document is a comprehensive reference manual for the Digital Equipment Corporation PDP-12 computer, detailing its architecture, operation, and programming capabilities. The PDP-12 is a versatile digital computer featuring two distinct operating modes: LINC (Laboratory Instrument Computer) and PDP-8, each with its own instruction set. Its central processor operates on a 12-bit word length with a 1.6 microsecond cycle time, and basic core memory capacity is 4K 12-bit words, expandable to 32K.

The manual covers:

• System Overview: General description, central processor architecture (registers like Accumulator, Program Counter, Memory Address, Link, etc.), memory organization in both LINC and PDP-8 modes, and I/O facilities.
• Controls and Indicators: Detailed descriptions of the console controls, data terminal, CRT display (Type VR12), LINCtape transports (Type TU55), and Teletype (Model 33 ASR).
• Programming: In-depth explanations of programming in LINC mode (including instruction formats, data transfers, arithmetic, logic, comparison, half-word operations, program control, shifts/rotates, skips, and special functions) and PDP-8 mode (memory organization, addressing methods, standard instructions, program interrupt, and the Extended Arithmetic Element Type KE12).
• Input/Output Bus: Description of programmed data transfers, data break transfers, the program interrupt facility, interface design and construction using FLIP-CHIP modules, and IOT (Input/Output Transfer) allocations.
• Peripheral Devices: Comprehensive details on various peripherals, including Teletype models, real-time clocks (KW12-A, B, C), disk storage systems (DF/DS32, RF/RS08, RK8), magnetic tape controls (TC58), line printers (LP12, LP08), card readers (CR12, CM12), incremental plotters (XY12), high-speed paper tape punch/reader (PC12), data buffers (DB12-P, N), power fail/restart options (KP12), and analog-to-digital/digital-to-analog converters (AF01-A, AA01-A).
• Program Library & Diagnostics: A listing of available PDP-12 and PDP-8 programs (including assemblers, utilities, FORTRAN, debugging tools, and scientific subroutines) and diagnostic programs for testing various system components.
• Appendices: Provide instruction lists for LINC and 8 modes, I/O bus instructions, Teletype and card reader codes, cable connections, and mathematical data.

This manual serves as a comprehensive resource for understanding the PDP-12's hardware, software, and interfacing capabilities.