cc65/asminc/cbm.mac

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; Convert characters to screen codes
; Macro that converts one character.
; scrbyte() can be used as an instruction operand
.define scrbyte(code) (<(.strat ("h@dbdlhh", code >> 5) << 4) ^ code)
; Helper macro that stores one character
.macro _scrcode char
.if (char < 256)
.byte scrbyte {char}
.else
.error "scrcode: Character constant out of range"
.endif
.endmacro
.macro scrcode arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9
; Bail out if next argument is empty
.if .blank ({arg1})
.exitmacro
.endif
; Check for a string
.if .match ({arg1}, "")
; Walk over all string chars
.repeat .strlen (arg1), i
_scrcode {.strat (arg1, i)}
.endrepeat
; Check for a number
.elseif .match (.left (1, {arg1}), 0)
; Just output the number
_scrcode arg1
; Check for a character
.elseif .match (.left (1, {arg1}), 'a')
; Just output the character
_scrcode arg1
; Anything else is an error
.else
.error "scrcode: invalid argument type"
.endif
; Call the macro recursively with the remaining args
scrcode arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9
.endmacro