Always print the mouse cursor, even if coordinates haven't changed.

This makes sure that the cursor is always visible, even if the program
has written text to the screen (only valid for non-P/M mouse callbacks).

libsrc/atari/mou/atrtt.s

@@ -118,12 +118,8 @@ INSTALL:
         dex
         bpl     @L1
 
-; Be sure the mouse cursor is invisible and at the default location. We
-; need to do that here, because our mouse interrupt handler doesn't set the
-; mouse position if it hasn't changed.
+; Be sure the mouse cursor is invisible and at the default location.
 
-        php
-        sei
         jsr     CHIDE
         lda     XPos
         ldx     XPos+1
@@ -131,7 +127,6 @@ INSTALL:
         lda     YPos
         ldx     YPos+1
         jsr     CMOVEY
-        plp
 
 ; Done, return zero (= MOUSE_ERR_OK)
 
@@ -352,15 +347,18 @@ IRQ:
 
 @L02:   lda     PADDL0
         cmp     #228
-        beq     @Dont
+        beq     @Cont                   ; CF set if equal
         lda     PADDL1
-        cmp     #228
-        bne     @Do
-@Dont:  jmp     @Done
+        cmp     #228                    ; CF set if equal
 
-@Do:    lda     visible
-        beq     @L03
+@Cont:  lda     visible
+        beq     @Go
+        php                             ; remember CF
         jsr     CHIDE
+        plp                             ; restore CF
+
+@Go:    bcc     @L03
+        jmp     @Show
 
 @L03:   ldx     #0
         stx     XPos+1
@@ -484,7 +482,7 @@ IRQ:
         tya
         jsr     CMOVEY
 
-        lda     visible
+@Show:  lda     visible
         beq     @Done
         jsr     CSHOW