mac68k-asm

68000 assembler toolchain for the classic Macintosh.

v1.2.1 MIT Linux macOS

Source on GitHub Releases & .debs

Install

macOS (Homebrew) - the formula builds from source:

brew install bircher988/tap/mac68k-asm

Debian, Ubuntu, Raspberry Pi OS - every release has a .deb for arm64 (Raspberry Pi) and amd64 (PC): 

wget https://github.com/bircher988/mac68k-asm/releases/download/v1.2.1/mac68k-asm_1.2.1_arm64.deb
sudo apt install ./mac68k-asm_1.2.1_arm64.deb      # or ./mac68k-asm_1.2.1_amd64.deb on a PC

From source (Linux, macOS, any Unix) - needs only a C compiler and make:

git clone https://github.com/bircher988/mac68k-asm.git
cd mac68k-asm && make && sudo make install

mac68k-asm version shows what is installed.

About mac68k-asm

mac68k-asm builds applications for the first Macs (Mac 128K, 512K and Plus, 64K ROM, System 3.x) from 68000 assembler sources. One small C program contains the assembler, the linker, the resource compiler and a MacBinary writer. The result goes onto a floppy image with mac68k-disk and runs on real hardware just as in an emulator.

The source dialect and the project files (.Job, .Link, .R) follow the Macintosh assembler conventions of the mid-1980s, so projects written for the Macintosh 68000 Development System (MDS) should build too.

Quick start

git clone https://github.com/bircher988/mac68k-asm.git
cd mac68k-asm
make                                  # needs only a C compiler and make
./mac68k-asm build example/Hello.Job -o out

out/Hello.bin is the finished application as MacBinary. Put it on a disk image and boot it in Mini vMac or on the real machine:

mac68k-disk new Apps.dsk            # 400K MFS, readable by every 68k Mac
mac68k-disk add Apps.dsk out/Hello.bin

Commands

mac68k-asm build <File.Job>  [-o outdir] [-I dir]...   run a .Job file (ASM / LINK / RMAKER)
mac68k-asm link  <File.Link> [-o outdir] [-I dir]...   assemble and link
mac68k-asm res   <File.R>    [-o outdir] [-I dir]...   compile a resource file
mac68k-asm asm   <Module.Asm>... [-I dir]... [-o out.raw] [-l listing]
mac68k-asm version | help

What is inside

  • Assembler for the 68000 in the MDS dialect: Include, macros with %1..%9, IF/ELSE/ENDIF, EQU/SET/DC/DCB/DS, local @labels, register aliases. It iterates until all addresses are stable and picks short branches where they reach.
  • DS variables live in the A5 globals area, not in the code, exactly as on the original system; labels are addressed PC-relative.
  • Linker for one CODE segment, with a .MAP of segment and globals sizes and a listing with addresses and bytes.
  • Resource compiler in the format of the MDS RMaker: WIND, DLOG, ALRT, DITL, MENU, BNDL, FREF, STR and GNRL for anything else, so an application gets its own Finder icon.
  • Include files with every Toolbox and OS trap and the system equates, under the classic names. Each trap knows its ROM: using a Mac Plus (128K ROM) trap in a program for the 64K ROM gives a warning.
  • Diagnostics name the file and line of the original source, also inside includes.

Not implemented yet: several CODE segments with a jump table (/Segment in .Link). The full reference is the README on GitHub.

Licence

MIT, including the include files: they are generated from the trap numbers and equate values documented in Inside Macintosh.

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