167 – The Apollo Guidance Computer
Guest: Frank O’Brien Host: Markus Voelter Shownoter: Stefaan Rillaert
This episode is a mix between computer architecture, programming and (historic) space flight. We cover the ins and outs of the Apollo Guidance Computer. Our guest ist Frank O’Brien, who wrote an incredibly detailed book about this machine. In the episode we cover the hardware architecture, the instruction set, the various layers (native, executive and interpreter) as well as some mission programs.
Overview hardware and software0:08:38
Apollo Guidance Computer | Mid 60s NASA/MIT documentary 'Computer for Apollo' | CPU | Computer memory | Core rope memory | 'Weaving software into core memory by hand' | History digital computers | History integrated circuits | Octal | Assembly level programming | Interpreter | Multiprogramming | Apollo Command Module | Apollo Lunar Module | Saturn Launch Vehicle Digital Computer | Apollo Abort Guidance System
Floating point | Signed number representations | Ones' complement | Two's complement | Parity bit | State vector | Memory bank | Processor register | Bit shifting | Direct memory access | Opcode | Index register | Call stack | Global variable | Interrupt | Verb and noun codes on Virtual AGC | Apollo 15 Delco LM Manual with information about DSKY and lists of verbs and nouns
Executive or Operating System1:14:37
Operating system | 'The Apollo guidance computer: Software' in 'Computers in Spaceflight: The NASA Experience' | Memory management | I/O | API | Cooperative multitasking | Preemptive multitasking | Watchdog | Core sets and Apollo 11 landing | Virtual machine (VM) | p-code | Intermediate language | Polish notation | Forth | Programmer's Manual AGC Assembly Language | Autopilot | Low-level programming language | High-level programming language