Getting started

Hello world example

Save the following as hello_world.mfk:

import stdio

void main(){
    putstrz("hello world"z)
    while(true){}
}

Compile it using the following commandline:

java -jar millfork.jar hello_world.mfk -o hello_world -t c64

Run the output executable (here using the VICE emulator):

x64 hello_world.prg

The following options are obligatory when compiling your sources:

-o FILENAME – specifies the base name for your output file, an appropriate file extension will be appended (prg for Commodore, xex for Atari computers, a2 for Apple, asm for assembly output, lbl for label file, inf for BBC file metadata, dsk for PC-88, tap for ZX Spectrum, rom for MSX cartridges, com for CP/M, nes for Famicom, bin for Atari 2600)
-t PLATFORM – specifies the target platform. Each platform is defined in an .ini file in the include directory. For the list of supported platforms, see Supported platforms

You may be also interested in the following:

-O, -O2, -O3, -O4 – enable optimization (various levels)
-finline – automatically inline functions for better optimization
-fipo – enable interprocedural optimization
-s – additionally generate assembly output (if targeting Intel 8080/8085, use --syntax=intel or --syntax=zilog to choose the preferred assembly syntax)
-fsource-in-asm – show original Millfork source in the assembly output
-g – additionally generate a label file, in format compatible with VICE emulator
-r PROGRAM – automatically launch given program after successful compilation
-Wall – enable all warnings
--help – list all commandline options

For the comprehensive list of command-line options, see Command-line options.