The Compiler

The compiler assembles .bmasm source into .prg or .bin files that run on the Commander X16.

It takes standard 6502 / 65c02 syntax. On top of that you can embed C# that runs at build time and writes assembly for you; that stage is the Template Engine, and it runs before the compiler sees the file.

The three kinds of line

The template engine expands any embedded C# first. What reaches the compiler is three kinds of line:

• An opcode. Starts with a valid 6502 / 65c02 mnemonic, for example lda #$00.
• A directive. Starts with a ., for example .segment or .const. Directives set up structure, scopes, data and constants. A line that is just a word starting with . and ending with : is a label.
• A comment. Starts with ;.

Comments

; starts a comment, whether it follows code on a line or sits on a line of its own. The compiler also accepts // on a directive line. On a C# line, use C# comment syntax.

lda #$00        ; a comment
.const width 40 // also a comment

Directives

A directive line starts with .. Parameters are positional, or given as name=value pairs:

.const name=example, value=$1234
.const example $1234

The Directives page is the full list. The parts with more to them have their own pages: Segments, Scopes, Labels and Expressions.