Comanche055-C89

ANSI C89 port of the Apollo 11 Guidance Computer (AGC), specifically the Command Module (Comanche 055 / Colossus 2A).

Translated from the original AGC assembly source at chrislgarry/Apollo-11.

Overview

Self-contained, single-threaded console application.

Faithfully reproduces AGC fixed-point arithmetic, the executive job scheduler, waitlist timer system, and DSKY verb/noun interface.

Platform Support

Primary development and support targets are Windows and Linux.

Frontend availability by platform:

Frontend	Windows	Linux	macOS
Console	Yes	Yes	Yes
GUI	Yes	No	No
Web UI	Yes	Yes	Yes

Implemented:

• P00 — CMC Idling
• V82 / R30 — Orbital parameters (apogee, perigee, TFF)
• V16 N36 — Mission clock
• V35 — Lamp test
• V36 — Fresh start
• V37 — Program select
• V21–V25 — Data load
• V06 / V05 — Decimal / octal display

Stubbed: All other programs (alarm on selection).

Build

Source is in Comanche055-C89/.

CMake

cmake -B build

cmake --build build

Usage

./comanche055

Or skip the menu with a display mode argument:

./comanche055 <console|gui|web>

Keyboard mapping is shown on the DSKY display:

Key	Function
V	VERB
N	NOUN
E	ENTR
0–9	Digits
+ / -	Sign
C	CLR
R	RSET
P	PRO
K	KEY REL
Q	Quit

Example: type V 3 5 E for lamp test, V 1 6 E N 3 6 E for mission clock.

Screenshots

ASCII Terminal	Win32 GDI	Web UI

Roadmap

• Graphical DSKY interface
• Full program implementations (P20–P25, P30–P39, P40–P47, P51–P53, P61–P67)
• State vector propagation and orbit integration
  • Compute spacecraft position/velocity using AGC state vectors, burns, and gravity models
• IMU simulation
  • Model gyros/accelerometers, platform alignment, and drift so guidance logic receives realistic inertial inputs
• Telemetry downlink display
  • Decode AGC downlink words/frames and present key flight values and alarms in real time

License

Public domain, consistent with the original AGC source code.