Start on FILE i/O

rom/wozmon.s

@@ -33,7 +33,7 @@ BACKSPACE:      DEY                    ; Back up text index.
                 BMI     GETLINE        ; Beyond start of line, reinitialize.
 
 NEXTCHAR:
-                LDA     $BC01          ; Check status.
+                LDA     IO_KBD         ; Check status.
                 BMI     NEXTCHAR       ; Loop until ready.
                 STA     IN,Y           ; Add to text buffer.
                 JSR     ECHO           ; Display character.
@@ -165,5 +165,5 @@ PRHEX:
                 ADC     #$06           ; Add offset for letter.
 
 ECHO:
-                STA     $BC00          ; Output character.
+                STA     IO_SCREEN      ; Output character.
                 RTS                    ; Return.