asig / brainfuck128

A Brainfuck interpreter and compiler for the Commodore 128.

How to run brainfuck

Interpreter

For the interpreter, just execute make run

If you don't know what cool things you could do in Brainfuck, how about trying this? ++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.

Compiler

There is also a brainfuck compiler that generates native Commodore 128 "prg"s that can be loaded via dload.

To run the compiler, execute make bfc128.prg; then dload "bfc128.prg" in VICE and just run it.

The compiler will ask you for the program, as well as the file name of the prg it should create

Limitations

The data pointer is 8 bit, so you're limited to 256 bytes of data.

Memory layout

$1c01 - $1cff: Standard BASIC header and padding $1d00 - $1dff: 256 bytes of data $1e00 - ...: Executable code

Register usage

The X register is used as the data pointer

Code patterns

Code generation

> | INX
< | DEX
'+' | INC $1D00,X
'-' | DEC $1D00,X
'.' | LDA $1D00,x; JSR $FFD2
',' | JSR $FFCF; STA $1D00,X
'[' | LDA $1D00,X; BNE +3; JMP XXXX
']' | LDA $1D00,X; BEQ +3; JMP XXXX

Random other bits

How to start the emulator with "file system drive"

x128 \
    -fs8 `pwd` \
    -fs8convertp00 \
    -iecdevice8

Writing to floppy images in x128

It seems that you can only write to disk images in x128 if you set "Use IEC drive" to true.