3.2. Dialects

LWASM supports all documented MC6809 instructions as defined by Motorola. By default, this does not include any MC6800 compatibility instructions. As of LWASM 4.11, those compatibility instructions can be enabled using the --6800compat option or the 6800compat pragma. It also supports all known HD6309 instructions. While there is general agreement on the pneumonics for most of the 6309 instructions, there is some variance with the block transfer instructions. TFM for all four variations seems to have gained the most traction and, thus, this is the form that is recommended for LWASM. However, it also supports COPY, COPY-, IMP, EXP, TFRP, TFRM, TFRS, and TFRR. It further adds COPY+ as a synomym for COPY, IMPLODE for IMP, and EXPAND for EXP.

By default, LWASM accepts 6309 instructions. However, using the --6809 parameter, you can cause it to throw errors on 6309 instructions instead.

The standard addressing mode specifiers are supported. These are the hash sign ("#") for immediate mode, the less than sign ("<") for forced eight bit modes, and the greater than sign (">") for forced sixteen bit modes.

Additionally, LWASM supports using the asterisk ("*") to indicate base page addressing. This should not be used in hand-written source code, however, because it is non-standard and may or may not be present in future versions of LWASM.