1
0
mirror of https://github.com/KarolS/millfork.git synced 2024-11-01 05:05:32 +00:00
millfork/include/encconv.mfk
2019-09-04 01:14:14 +02:00

119 lines
2.0 KiB
Plaintext

#if ENCODING_SAME
#if ARCH_6502
inline byte __byte_identity(byte a) { ? rts }
#elseif ARCH_I80
#pragma zilog_syntax
inline byte __byte_identity(byte a) { ? ret }
#else
inline byte __byte_identity(byte a) = a
#endif
alias from_screencode = __byte_identity
alias to_screencode = __byte_identity
#else
alias from_screencode = __from_screencode
alias to_screencode = __to_screencode
#endif
// conversions for particular encoding pairs:
#if ARCH_6502
asm byte petscii_to_petscr(byte a) {
cmp #$20
bcc __petscii_to_petscr_ddRev
cmp #$60
bcc __petscii_to_petscr_dd1
cmp #$80
bcc __petscii_to_petscr_dd2
cmp #$a0
bcc __petscii_to_petscr_dd3
cmp #$c0
bcc __petscii_to_petscr_dd4
cmp #$ff
bcc __petscii_to_petscr_ddRev
lda #$5e
rts
__petscii_to_petscr_dd2:
and #$5f
rts
__petscii_to_petscr_dd3:
ora #$40
rts
__petscii_to_petscr_dd4:
eor #$c0
rts
__petscii_to_petscr_dd1:
and #$3f
rts
__petscii_to_petscr_ddRev:
eor #$80
rts
}
asm byte petscr_to_petscii(byte a) {
cmp #$20
bcs __petscr_to_petscii_40
ora #$40
rts
__petscr_to_petscii_40:
cmp #$40
bcs __petscr_to_petscii_60
rts
__petscr_to_petscii_60:
cmp #$60
bcs __petscr_to_petscii_80
eor #$80
rts
__petscr_to_petscii_80:
cmp #$80
bcs __petscr_to_petscii_a0
eor #$c0
rts
__petscr_to_petscii_a0:
cmp #$a0
bcs __petscr_to_petscii_c0
eor #$80
rts
__petscr_to_petscii_c0:
eor #$40
rts
}
asm byte atascii_to_atasciiscr(byte a) {
and #$7f
cmp #$20
bcs __atascii_to_atasciiscr_60
ora #$40
rts
__atascii_to_atasciiscr_60:
cmp #$60
bcs __atascii_to_atasciiscr_end
sec
sbc #$20
__atascii_to_atasciiscr_end:
rts
}
asm byte atasciiscr_to_atascii(byte a) {
and #$7f
cmp #$40
bcs __atascii_to_atasciiscr_60
clc
adc #$20
rts
__atascii_to_atasciiscr_60:
cmp #$60
bcs __atascii_to_atasciiscr_end
and #$1f
__atascii_to_atasciiscr_end:
rts
}
#endif