initial patch from #1972

libsrc/plus4/crt0.s

@@ -10,7 +10,6 @@
         .import         callmain, zerobss
         .import         __INTERRUPTOR_COUNT__
         .import         __HIMEM__                       ; Linker generated
-        .importzp       ST
 
         .include        "zeropage.inc"
         .include        "plus4.inc"
@@ -121,7 +120,7 @@ L2:     lda     zpsave,x
 ; Place the program return code into BASIC's status variable.
 
         pla
-        sta     ST
+        sta     STATUS
 
 ; Restore the stack pointer.
 

libsrc/plus4/kreadst.s

@@ -7,12 +7,11 @@
         .export         READST
 
         .include        "plus4.inc"
-        .importzp       ST
 
 ; Read the status byte from the zero page instead of banking in the ROM
 
 .proc   READST
-        lda     ST                      ; Load status
+        lda     STATUS                  ; Load status
         rts                             ; Return to caller
 .endproc
 

libsrc/plus4/status.s

@@ -1,5 +1,15 @@
 ;
-; Oliver Schmidt, 2012-09-30
+; Stefan Haubenthal, 2023-01-16
 ;
 
-        .exportzp       ST := $90       ; IEC status byte
+        .export         initst
+
+        .include        "plus4.inc"
+
+.proc   initst
+
+        lda     #$00
+        sta     STATUS
+        rts
+
+.endproc