UTTORI ASM · IN DEVELOPMENT

Source syntax

Write numbers, labels, comments, and instructions in Uttori ASM source.

SNES behavior

Encoding & Case

Source files are read as UTF-8. Mnemonics and directive keywords are case-insensitive. Symbol spelling is preserved and should be treated as intentional. The fixtures favor lowercase directives and uppercase hardware mnemonics, which is pleasantly readable but not mandatory.

Numbers

Negative and unary-plus values are accepted. ~value and Asar-style !value perform bitwise NOT when ! cannot begin a define name. <:value shifts a value right by 16 bits. It is retained for compatibility with sources that use the form.

The 65C816 encoder also recognizes bank shorthand such as $12:3456. See the Asar example bank_shorthand.asm:

org $008000
	main:
		lda #<:main
		lda #<:test_label
		lda #bank(other_test)

base $038000
	test_label:

base $028000
	other_test:

Comments, Continuation, & Inline Commands

A semicolon begins a comment unless it appears inside a double-quoted string:

lda #$0F ; this vanishes before parsing
db "semicolon; retained"

End a line with \ or , to continue the command on the next physical line:

db $01, $02,
   $03, $04

function scale(value) = value * \
  4

Whitespace-surrounded colons split multiple statements on one line:

fillbyte $FF : fill $20

Colons inside quoted strings are safe. A label colon directly attached to a name remains a label colon.

Quotes & Directive Prefixes

Single and double quotes are accepted in several tokenized contexts. String data and expression string arguments should normally use double quotes. @ may prefix a recognized directive, so @org $008000 routes to org. It does not create a second directive family.

Braces { and } are accepted compatibility no-ops. They can make nested namespace source easier on human retinas, but they do not create block scope by themselves:

namespace Graphics
{
  Upload:
    rtl
}
namespace off

6502 family behavior

The plugin owns two dialects. 65xx.raw uses the core native profile. 65xx.ca65-raw and 65xx.nes use the ca65 profile.

Encoding & Case

Source files are read as UTF-8. Mnemonics and directive keywords are case-insensitive. Symbol spelling is preserved and should be treated as intentional. The fixtures favor lowercase directives and lowercase or mixed-case mnemonics. Either works.

Numbers

Negative and unary-plus values are accepted. Immediate #-1 is legal for an 8-bit immediate (signed). Addresses stay unsigned.

ca65 unary byte extracts are <value, >value, and ^value for low, high, and bank bytes. Native sources that want the same thing use lobyte() / hibyte() on a ca65 target, or & $FF / >> 8 anywhere.

Comments, Continuation, & Quotes

A semicolon begins a comment unless it appears inside a double-quoted string:

lda #$0F ; this vanishes before parsing
.byte "semicolon; retained"

End a line with \ or , to continue the command on the next physical line. String data and expression string arguments should normally use double quotes.