From 9e155eb096412bc38e3bb71fbcf292743eb7c149 Mon Sep 17 00:00:00 2001
From: Christian Groessler <chris@groessler.org>
Date: Tue, 14 Jan 2014 13:59:42 +0100
Subject: [PATCH] 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 | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/libsrc/atari/mou/atrtt.s b/libsrc/atari/mou/atrtt.s
index 9d2dac1c9..f58838720 100644
--- a/libsrc/atari/mou/atrtt.s
+++ b/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
 
-- 
2.39.5