Files
open-roms/c64/kernal/rs232/rs232_count_channels.s
T

30 lines
322 B
ArmAsm

// #LAYOUT# STD * #TAKE
// #LAYOUT# * KERNAL_0 #TAKE
// #LAYOUT# * * #IGNORE
//
// Sets .X to number of open RS-232 channels
//
#if HAS_RS232
rs232_count_channels:
ldx #$00
ldy LDTND
!:
dey
bmi close_rs232_search_done
lda FAT, y
cmp #$02
bne !-
inx
bpl !- // branch always
rts
#endif