p125c.asm

        .include "//os/h/:modules.h"
        #inc_k "io"
        #inc_s "file"

        *=2000
        
loop    ldx #2
        jsr chkin
        
        jsr chrin
        ldy status
        
        cmp #64
        bcc output
        
        cmp #96
        bcs notblk3
        
        ;clc ... carry is already clear
        adc #128
        bne output
notblk3  

        ;sec ... carry is already set
        sbc #32

output  pha
        jsr clrchn

        ldx #3
        jsr chkout
        
        pla
        jsr chrout
        
        jsr clrchn
        cpy #0
        beq loop
        
        rts