Operating systemsApple Classic Mac OS › Macintosh System 1

Macintosh System 1

1984

The 1984 operating system that launched the original Macintosh, introducing the desktop metaphor, windows, icons and the mouse to the mass market.

Machines

Chips

Reference & documentation

External technical references for programming Macintosh System 1 and for writing emulators.

ResourceTypeNotes
MC68000 Semiconductor Technical Data (Datasheet) ↗DatasheetElectrical characteristics, DC/AC bus timing parameters
Apple MFS on-disk format notes (CiderPress2) ↗FormatByte-level Macintosh File System volume layout
Macintosh resource fork format (Kaitai Struct) ↗FormatFormal binary spec of resource fork structure
M68000 Family Programmer's Reference Manual ↗Instruction setFull opcode encodings for every M68000 instruction
Inside Macintosh: Trap Manager ↗Interrupt listA-line trap dispatch: OS and Toolbox traps
Guide to the Macintosh Family Hardware (2nd Ed.) ↗Memory mapFull 68000 address map: RAM, ROM, VIA, SCC, IWM
MC68000 Datasheet pin assignments ↗Pinout64-pin DIP signal names and pin assignments
Inside Macintosh, Volume I ↗ProgrammingToolbox and OS programming reference for 68K Mac
Macintosh 128K ROM Image ↗ROMs64K 128K ROM dump, runs in Mini vMac
Inside Macintosh, Volume II (1984) ↗ReferenceOS core: File/Memory/Device managers reference
Mini vMac Source (GitHub) ↗SourceMac Plus emulator C source; hardware emulation reference
resource_dasm ↗ToolResource fork and 68k application disassembler