Multibyte constant

This macro allows including long hexadecimal constants on one line, like an arbitrary extension of the .dbyt (2 byte big endian constant). <source>

mbyt.s

Multibyte constant macro for ca65

Copyright 2013 Damian Yerrick

Copying and distribution of this file, with or without

modification, are permitted in any medium without royalty provided

the copyright notice and this notice are preserved in any source

code copies. This file is offered as-is, without any warranty.

.macro mbyt_hex2nibs highnib, lownib .local highdig, lowdig

 ; "dec0de" the hex nibbles
 .if highnib >= 'A' && highnib <= 'F'
   highdig = highnib - 'A' + 10
 .elseif highnib >= 'a' && highnib <= 'f'
   highdig = highnib - 'a' + 10
 .elseif highnib >= '0' && highnib <= '9'
   highdig = highnib - '0'
 .endif
 .if lownib >= 'A' && lownib <= 'F'
   lowdig = lownib - 'A' + 10
 .elseif lownib >= 'a' && lownib <= 'f'
   lowdig = lownib - 'a' + 10
 .elseif lownib >= '0' && lownib <= '9'
   lowdig = lownib - '0'
 .endif
 .byte highdig * $10 + lowdig
 ;.out .sprintf(".byte %02x", highdig * $10 + lowdig)

.endmacro

.macro mbyt inbytes

 ; thanks to thefox who recommended .set
 .local pos
 pos .set 0
 .out .sprintf("%s", inbytes)
 .repeat .strlen(inbytes)
   .if pos < .strlen(inbytes)
     nib .set .strat(inbytes, pos)
     ; these characters can be used as separators
     .if (nib = ' ' || nib = ',' || nib = '$' || nib = '_')
       pos .set pos + 1
     .else
       mbyt_hex2nibs nib, {.strat(inbytes, pos + 1)}
       pos .set pos + 2
     .endif
   .endif
 .endrepeat

.endmacro

use it like this

mbyt "09F91102 9D74E35B D84156C5 635688C0"

</source>

External links

• Ned Batchelder: Hex words has test cases
• Alternate implementation by thefox