1
0
mirror of https://github.com/KarolS/millfork.git synced 2024-11-01 05:05:32 +00:00
millfork/docs/various/asmdiff.md
2020-07-31 01:57:10 +02:00

37 lines
1.3 KiB
Markdown

[< back to index](../doc_index.md)
# Differences in assembly
## Syntax
* High and low bytes of an 16-bit value are acquired using the `hi` and `lo` functions, not the `>` and `<` operators.
* Anonymous labels and local labels are not supported.
All labels defined in assembly are global.
Colons are required in label declarations.
* Macros are inserted using the `+` operator.
* Raw bytes are inserted using the Millfork array syntax, not with any pseudoopcode (like `!byte`, `db` or `fcb`)
* Assembly blocks cannot contain definitions of constants or variables.
* 6502: To enforce zero-page addressing, wrap the argument in the `lo` function: `lo(arg)`
* 6502: To enforce absolute addressing, add a 16-bit zero to the argument: `0000 + arg`
* GameBoy: The $FF page loads/stores are written `LDH (C),A`, not `LD ($FF00+C),A`.
* GameBoy: The loads/stores that postincrement/postdecrement HL write the HL register as `HLI` or `HLD`, not `HL+` or `HL-`
* Z80: Indexing using the index register uses the `IX(1)` syntax, not `(IX+1)` or `1(IX)`.
* Z80: Most undocumented instructions are not supported. The only one supported is `SLL`.
* 6809: `0,X` is assembled the same as `,X`.
* 6502: To enforce direct-page addressing, prepend the argument with `<`: `<arg`.