6502.org

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rasm infile[.end][;/:] [output[.end]] [listfile]

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+ - * / ;basic arithmetic
> ;Hi-Byte of value
< ;Lo-Byte of value
~ ;NOT
! ;OR
& ;AND
^;XOR
>> ;SHR
<< ;SHL
(..) ;parentheses for more complicated math - they can't be first place in a statement LDA (xx),y => you have to write LDA +(1+3)*5,y to be not confused w/ addressing mode
?[i]<label>[/i] ;returns 1 if the label is undefined or if a library label is unused
! ;returns 0 if the label is undefned or a library is unused
++ --			;post- or pre-inc-/decrement, like in c
* ;also is the program counter
=,<>,>=,<= ;comparison, returns 1 or 0 if true or false

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;this is a comment
/// and this
is a block of
/// coment -- for commenting out sections of code in a fast way

.CODE +|-	;turns code generation on or off, used for generating virutal tables:
*=0 ;zp space
.cod -
zpptr1 .wor 0
zpptr2 .wor 0
tmpbyte .byt0
.cod +
*=$c000 ;start of actual program

.ILL +|- ;allows or forbids NMOS undocumented opcodes
.CPU cpu ;defines target CPU: 6502,65N02,65N02_ILL,65C02,Rockwell65C02,WDC65C02,65C02S,WDC65C816 - but olny NMOS is fully implemented yet

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.INC name		;includes the file "name" and processes it as asm-code
.BIN name|"name" [,+<skip>][,<len>] ;file is incorporated as binary, if +skip is given, <skip> bytes are skipped, if <len> is given this is the number of bytes to be incorporated.
.PATH "list" ;adds directories where to look for .inc - just like DOS PATH
.EXPORT "filename" ;defines the name of a file where to export label values - for generating ROM-maps
.EXPORT <libraryname>|<makname> ;macros or libraries are exported

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.BYTE <val>[,val...]	;list of byte values
.WORD <val>[,val...]	;liste of word values
.FILL <address>[,byteval=$FF] ;fill from * to address-1 with byte-val ($ff is default) - .e.g. for filling space till Vectors: .fill $fffa,$ea
.FLOAT <float>[,float] ;produces floating point data in 5--byte-CBM format
.GRAPH ;producing data for character maps or C64-Sprites
		.GRAPH 10100011		;single-color
		.GRAPH ..--||##		;multi-color (..=00,--=01,||=10,##=11)

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.ASC "string"|byteval[,...]	;liste of strings and/or byte values
.ASC "Hallo\$12\x34\255 ;= .asc "Hallo",$12,$34,$ff
.ASC00 ;like .asc but adds a 0 at the end of string
.ASC80 ;like .asc but the last character gets OR$80 (=for printstr routines or like the CBM BASIC token tables are done)
.ASCLEN ;like asc, but the length of the string is added [i]in front of[/i] the string, e.g. .asclen "Hallo" = .asc 5,"Hallo" - for fast pascal-style strings
.ASCREV ;like .asclen but the	string is in reversed order .ascrev "Hallo" = .asc 5,"ollaH"

.TRANS byte[-byte]|"cc"=byte[-byte]|"cc"[,...] ;controls string translation:
.trans 1=2 ;in .asc-statemtents values of 1 would be replaced with 2
.trans "A-Z"="a-z" ;all capital letters would be replaced with their small counterpart
.trans "a"="^a"  ;"a" would be replaced with control-a =$01, i.e. value and $3f
;| is like ^but value or $80; ~ is value and $3f or $80
.trans \<text>=<byte> ; defines an escape-sequence:
.trans \white=5 ;in .asc you could write "Hal\whitelo" => .asc "Hal",5,"lo"
.trans without parameters  clears the translation table, i.e. every character is put to object file as is

.TRANS_PET graph|text ;.trans with values and escape-sequences for CBM PETSCII
.TRANS_POKE graph|text ;.trans with values fo CBM screen codes

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.ERR message ;produce error message, e.g. a library needs some function defined which is forgotten the main code

.WRITE "xx"|[f]ausdruck[,...]	;prints either string "xx" or the result of the expression - without CR/LF at the end
;result can be formatted with preceding....
.write $val1,%val2,!val3 ;values are printed as hexadecimal, binary or simple decimal numbers
.write wval, bval ;hexadecimal output formatted as word or byte (=4/2 digits)
.write 3#val ;value shall be printed with 3 digits
.write -5#val ;5 digits but right-aligned
					
.WRITELN   ;like .write but adding CR/LF

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<name> .BLK ;starts a block with local labels
.end <name> ;name must be identical to above - helps readability with longer blocks

or

.BLK <name>
.end <name>

In a block you can do
test .blk
#label1 ... ;this label will be visible in global scope
<label2 ... ;this label is visible in the surrounding block
.end test

.MAK [!]name [param,..]		;macro definition, is invoced with name or name paramlist or name (poaramlist)
...code ;in the code parameters are substituted
.END

.mak plot xval,yval
ldx #xval
ldy #yval
jsr plotfunc
.end

plot 123,myvalue  ;this will result in:
.blk
ldx #123
ldy #myvalue
jsr plotfunc
.end

plot 123,!myvalue ;here myvalue will be evaluated first - e.g. for counters that change their value constantly

.mak !hallo ... ;the macro generates no local labels, i.e. labels are visible in the next higher block


.LIB <name> ;a library function which is only incorporated if used by main code, usage is evaluated at the end of pass 1, code is placed there if used.
.end <name>

.lib testlib
...
#entry ... ;this defines an additional entry point, so you can access the libfn not only at the beginning
...
.end testlib 

.USES lib-fn ;markls a library function as used

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.IF expression			;if expression<>0 then assemble next block
		...code...
	.ELSE				;if expression=0 assemble this block
		...code...
.ENDIF

or alternatively as single-line .if:
.IF expression code			;no else statement and cannot be mixed with .if-style above

.FOR [name=]startval,endval[,step=1] ;	nomen est omen
	...code...			;in the code block, name will be replaced by the for's value
.END

.for @i=1,3
.byte @i
.end
=>
.byte 1
.byte 2
.byte 3

.for @i=1,3,2 ; you can add a step value
.byte @i
.end
=>
.byte 1
.byte 3

.foreach name1,[name2...] ;the line of code at the end will be repeated with every element of the list
elem1
elem2
...
.end .byte name1[,name2]

.foreach vector
reset
$ffd2
fancy+expression*here
.end .word vector

=>
.word reset
.word $ffd2
.word <whatever result this expression has>

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.SEGMENT <seg>		;different segments of code like code, data, variables,...
.end <seg>

.segment init ;(or exit)
...
.end init  ;=> segment for init (or clear-up) code, allows libraries to incorporate stuff for fire-up and shut-down. The segment is placed after the library code.

.segment data ;data with fixed value, will be incorporated in the file after lib/init/exit right before end of object file
.segment var ;data without fixed value, includes .cod - = generates no code just address space after the end of object file (if no *= is given)

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.cpu base=<adr> ;Assembler assumes bp is containing hi-byte of adr

.cpu base=check ;Assembler checks if address given is within basepage and issues error if not
.cpu base=ignore ;Assembler doesn't check if the address given is within basepage
.cpu base=deny ;Assembler forces absolute addressing (and rejects indirect basepage modes)

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.cpu base=$0400
.cpu base=ignore
sta $0412 ;=>85 12
sta $0034 ;=>85 34
sta ($0412),y ;=>91 12
sta ($0034),y ;=>91 12

.cpu base=deny
sta $0412 ;=> 8d 12 04
sta $0034 ;=> 8d 34 00
sta ($0412),y ;=>error
sta ($0034),y ;=>error

.cpu base=check
sta $0412 ;=>85 12
sta $0034 ;=>8d 34 00
sta ($0412),y ;=>91 12
sta ($0034),y ;=>error