Digital Museum: Colossus (2008)

Colossus was a real-time OS written by Miron Vranjes, Alex Fefer, Alex Roman, and Lukas Sydorowski at UWaterloo and lost to time for two decades. You're running an updated binary with loadable apps, BASIC, Zork, and a tiny LLM, but can also run the original binary compiled back in 2008, emulated byte-for-byte in your browser.

A pre-emptive multitasking kernel for the Freescale ColdFire MCF5307, featuring inter-process communication, dynamic memory management, device drivers, a timing calibration service, and a wall clock written in C++. This emulator faithfully reproduces the hardware down to the individual CPU opcodes.

CONSOLE OUTPUT

FREESCALE

CPU STATE

100%

EXECUTED 0

IPS ---

PROCESS ---

TIMER IRQs 0

MEMORY HEATMAP

System Commands
`%T`	Task manager — shows all processes, CPU%, priority, state
`%WS12:00:00`	Start wall clock at HH:MM:SS
`%WT`	Stop wall clock
`%C <pid> <pri>`	Set process priority (0=realtime .. 4=idle)
`%R <pid>`	Restart a terminated process
`%Q`	Shutdown
ECE354 Tests
`%X`	Start A3 → B2 → C2 message chain
`%Y`	Start A2 — intentional divide-by-zero exception
`%Z`	Start A1 → B1 → C1 message chain

System Commands
`%t`	Task manager — shows all processes, CPU%, priority, state
`%ws HH:MM:SS`	Start wall clock
`%wt`	Stop wall clock
`%p <pid> <pri>`	Set process priority (0=realtime .. 4=idle)
`%u <pid>`	Restart a terminated process
`%q`	Shutdown
Filesystem
`%l`	List all files
`%f <name>`	Display file contents
`%d <name>`	Delete a file
Loadable Apps
`%r calc.bin`	Load calculator app
`%r snake.bin`	Load snake app
Calculator (load first with %r)
`%c 42+8`	Arithmetic: + − * / % ^ log pi e
Snake (load first with %r)
`%s`	Start game
`↑↓←→`	Arrow keys to steer
`%s quit` / ESC	Quit game
Text Editor
`%e <name>`	Open or create a file
`%e <text>`	Append a line (while editing)
`%e print`	Show all lines with numbers
`%e del <n>`	Delete line n
`%e edit <n> <text>`	Replace line n
`%e save`	Save and close
`%e quit`	Close without saving
BASIC Interpreter
`%b <file.bas>`	Run a BASIC program
`%b <value>`	Supply INPUT value (when prompted)
`%b list`	List loaded program
`%b vars`	Show variables
Interactive Fiction (Z-Machine)
`%z <file.z3>`	Load and play a Z-machine game
`%z <command>`	Enter game command (when playing)
Llama2 LLM (INT8 Quantized)
`%a`	Generate a story
`%a <prompt>`	Generate from prompt (e.g. %a The cat)
Other
`%h`	Show help
ECE354 Tests
`%x`	Start A3 → B2 → C2 message chain
`%y`	Start A2 — intentional divide-by-zero exception
`%z`	Start A1 → B1 → C1 message chain

Upload .txt files, .bas BASIC programs, .z3 games, or compiled .elf apps. Files are stored in your browser and restored on refresh.

Building a C app for Colossus

Install the m68k-elf-gcc cross-compiler and download the SDK:

colossus_app.h app.ld

Write your app (hello.c):

#include "colossus_app.h"
extern uint32_t __bss_start, __bss_end;

void _start(void) {
    app_memset(&__bss_start, 0,
        (uint8_t*)&__bss_end
        - (uint8_t*)&__bss_start);
    sys_printf("Hello world!\r\n");
    c_exit();
}

Compile:

m68k-elf-gcc -O1 -m5200 -ffreestanding  \
  -nostdlib -nostartfiles -std=c99    \
  -Wl,--emit-relocs,-T,app.ld        \
  hello.c -o hello.elf

Upload hello.elf above, then run:

%r hello.bin

Your app is auto-relocated to a free memory slot. To register a % command, call kcd_register('g') and receive input with c_receive_message(KCD_PID). See colossus_app.h for the full API.