refactor countdown as a procedure call

mandel.s

@@ -1991,55 +1991,25 @@ update_status:
     lda FR0 + 1
     sta elapsed_work + 1
 
-    ;jsr IFP
-    ;jsr FASC
-    ;jsr draw_string
-
-    .macro countdown divisor, digits
-        .scope
-            ; count the hours
-            ldx #0
-        countdown_loop:
-            lda elapsed_work + 1
-            cmp #.hibyte(divisor)
-            beq countdown_lobyte
-            bcc countdown_done
-            bcs countdown_inc
-        countdown_lobyte:
-            lda elapsed_work
-            cmp #.lobyte(divisor)
-            bcc countdown_done
-        countdown_inc:
-            sec
-            lda elapsed_work
-            sbc #.lobyte(divisor)
-            sta elapsed_work
-            lda elapsed_work + 1
-            sbc #.hibyte(divisor)
-            sta elapsed_work + 1
-            inx
-            jmp countdown_loop
-        countdown_done:
-            lda digits,x
-            eor #$80
-            sta elapsed_digit
-            lda #.lobyte(elapsed_digit)
-            sta INBUFF
-            lda #.hibyte(elapsed_digit)
-            sta INBUFF + 1
-            jsr draw_string
-        .endscope
-    .endmacro
-
     draw_string_const str_space
-    countdown 36000, digits_space
-    countdown 3600, digits_zero
+    
+    .macro do_countdown divisor, digits
+        ldx #.lobyte(divisor)
+        ldy #.hibyte(divisor)
+        lda #.lobyte(digits)
+        sta INBUFF
+        lda #.hibyte(digits)
+        sta INBUFF + 1
+        jsr countdown
+    .endmacro
+    do_countdown 36000, digits_space
+    do_countdown 3600, digits_zero
     draw_string_const str_h
-    countdown 600, digits_zero
-    countdown 60, digits_zero
+    do_countdown 600, digits_zero
+    do_countdown 60, digits_zero
     draw_string_const str_m
-    countdown 10, digits_zero
-    countdown 1, digits_zero
+    do_countdown 10, digits_zero
+    do_countdown 1, digits_zero
     draw_string_const str_s
 
 skipped:
@@ -2101,3 +2071,45 @@ loop:
     jmp main_loop
 
 .endproc
+
+; digit string in INBUFF
+; divisor X/Y
+; clobbers temp, calls draw_string
+.proc countdown
+    divisor = temp
+    stx divisor
+    sty divisor + 1
+
+    ; count the hours
+    ldy #0
+countdown_loop:
+    lda elapsed_work + 1
+    cmp divisor + 1
+    beq countdown_lobyte
+    bcc countdown_done
+    bcs countdown_inc
+countdown_lobyte:
+    lda elapsed_work
+    cmp divisor
+    bcc countdown_done
+countdown_inc:
+    sec
+    lda elapsed_work
+    sbc divisor
+    sta elapsed_work
+    lda elapsed_work + 1
+    sbc divisor + 1
+    sta elapsed_work + 1
+    iny
+    jmp countdown_loop
+countdown_done:
+    lda (INBUFF),y
+    eor #$80
+    sta elapsed_digit
+    lda #.lobyte(elapsed_digit)
+    sta INBUFF
+    lda #.hibyte(elapsed_digit)
+    sta INBUFF + 1
+    jsr draw_string
+    rts
+.endproc