MMBasic for MacOS (MMB4M)

MMBasic is Geoff Graham's and Peter Mather's BASIC for the Colour Maximite and the PicoMite. Thomas Hugo Williams ported it to Linux as MMBasic for Linux. MMB4M takes that port and builds it for the Mac.

Install

With Homebrew:

brew tap TomSchimana/mmbasic
brew install mmbasic

By hand, download the zip for your Mac from the latest release:

• mmb4m-0.1.2-silicon.zip for Apple Silicon, any Mac with an M-series chip
• mmb4m-0.1.2-intel.zip for an Intel Mac

Each holds the single file mmbasic.

macOS blocks a downloaded program without an Apple developer certificate, and this one has none yet. Once per download:

xattr -dr com.apple.quarantine mmbasic
./mmbasic

Running MMB4M covers the PATH and the command line.

Running programs

mmbasic prog.bas          # run and exit
mmbasic -i prog.bas       # run, then stay at the prompt
mmbasic                   # prompt only

QUIT exits. At the prompt, Ctrl-C stops the running program and gives the prompt back; in batch mode it ends the run with exit code 130.

Colour Maximite 2 programs

Most run unchanged. The ones that do not are almost always graphics: MODE and PAGE do not exist here, and PRINT never draws to a surface.

Start the interpreter in Colour Maximite 2 mode and MODE, PAGE and the rest come back:

mmbasic -s "Colour Maximite 2" prog.bas

Colour Maximite 2 programs says what comes back and what does not.

MMB4M is not the CMM2 firmware. It is MMBasic for Linux 0.8, an alpha from its development branch, and its language follows MMBasic 6.0 for the PicoMite. The Colour Maximite 2 mode simulates the device name, MODE, PAGE and the controllers. That is enough to write and test a CMM2 program's logic at a desk; graphics, sound and timing are close, not identical.

What is different

The language is MMBasic 6, and each machine's page carries its current user manual: Colour Maximite 2, whose firmware is a separate release of MMBasic with a manual of its own, and PicoMite with PicoMite VGA, the manual MMB4L follows and therefore the one this port follows. This is what a Mac does differently.

What	On a Mac	Details
MODE, PAGE	There are no screen modes. A program opens its own window with GRAPHICS WINDOW 0, 640, 480 and draws into it. Both commands do work when MMB4M is started with -s "Colour Maximite 2"	Graphics
FRAMEBUFFER	Not implemented. Colour Maximite 2 mode does not bring it back, PicoMite mode does. GRAPHICS BUFFER with GRAPHICS COPY draws off-screen the same way	What MMB4M cannot do
PRINT	Writes to the terminal, never to a graphics surface, in Colour Maximite 2 mode as well. TEXT x, y, s$ draws onto the surface GRAPHICS WRITE selected	Graphics
SETPIN, PIN, PULSE, FLASH	A Mac has no microcontroller pins, so there is nothing to switch to	What MMB4M cannot do
Serial	Nothing above 230400 baud; macOS defines no higher rate, and setting one fails. Ports are named /dev/cu.*, which ls /dev/cu.* lists	What MMB4M cannot do
Timing	macOS is not a real-time system, so PAUSE and SETTICK drift more than on a microcontroller. SETTICK works, SETTICK FAST does not	What MMB4M cannot do
EDIT	Opens MMBasic's own full-screen editor in the terminal, the one both machines have: F1 saves, F2 saves and runs, ESC leaves. OPTION EDITOR VIM, VSCODE, NANO or a command of your own switches to another editor, OPTION EDITOR INTERNAL switches back	Editing programs
SAVE	Not needed: the file on disk is the program, and F1 in the editor writes it. SAVE "prog.bas" answers Unknown SAVE subcommand, because SAVE IMAGE does exist	Editing programs
GAMEPAD	DEVICE GAMEPAD OPEN and CLOSE instead, for a controller connected to the Mac. The function GAMEPAD() is not there	What exists here and not on a Colour Maximite 2 or a PicoMite
!cmd	At the prompt, short for SYSTEM: !ls lists the directory. !cd foo is the exception and becomes CHDIR "foo", because every other command runs in a forked process	Running MMB4M
MM.INFO$(DEVICE)	Answers MMB4L, the device this port is built from, so a program written for MMBasic for Linux recognises the machine it is on. Under -s it answers the simulated device, while MM.INFO$(DEVICE X) keeps answering MMB4L. That is how this release behaves. A later version may answer MMB4M instead, with a way to keep programs written for the Linux device working	What exists here and not on a Colour Maximite 2 or a PicoMite
CONSOLE	Sets the colours, the cursor and the title of the terminal. CONSOLE GETSIZE reads its size, which a terminal can change and neither machine's screen can	What exists here and not on a Colour Maximite 2 or a PicoMite
OPTION CODEPAGE	Decides how bytes 128 to 255 print. A terminal is Unicode and a Colour Maximite 2 screen is not, so OPTION CODEPAGE CMM2 is needed before a CMM2 program's box characters come out right. It lasts for the session, not beyond	Options
Command line	mmbasic prog.bas runs and exits, -i stays at the prompt afterwards, -d sets the starting directory, -s simulates another device, -l sets the log level, -v prints the version	Running MMB4M
CMM2 programs	Start with -s "Colour Maximite 2", or -s CMM2 for short. Do not switch device from inside a running program: that faults at the next graphics command	Colour Maximite 2 programs
PicoMite programs	Start with -s PicoMiteVGA, or one of PicoMiteHDMI, PicoMiteVGAUSB, PicoCalc, Game*Mite. MODE and FRAMEBUFFER come back, PAGE does not	PicoMite programs
This version	0.1.2, no known defects, and a list of what has been tried on a Mac and what has not	Known problems
Building it	One make, with the Xcode Command Line Tools and cmake. SDL2 is compiled in, so the result is a single file	Building MMB4M

This is not an official release

MMB4M is not maintained by the authors of MMBasic and carries no promise from them. The supported versions are MMBasic for Linux and real Colour Maximite 2 hardware.

Geoff Graham gave permission on 2026-08-25 on two conditions: the name "MMBasic" stays, and the original copyright message keeps appearing at startup. Both are met.

Credit and licence

MMBasic is the work of Geoff Graham and Peter Mather. MMBasic for Linux, including its graphics, sound and console, is the work of Thomas Hugo Williams, and it is his interpreter you are running. MMB4M changes what is needed to build and run it on a Mac and nothing else.

My thanks to Thomas Hugo Williams for years of work on MMB4L, and for the permission to build on it. Without that work there would be no Mac version.

The changelog records which MMBasic for Linux commit each version was built from.

MMBasic's own modified BSD licence, five numbered conditions, reproduced word for word in LICENSE.MMBasic. LICENSE says who holds what.

Alpha

MMB4M is at alpha status, built and tested by one person on one Apple Silicon Mac. Not everything has been tried; known problems says what has and what has not. If something does not work, open an issue or get in touch through schimana.net. Questions about MMBasic itself belong on The Back Shed.