From 00591676dcf5228d2389b118414ff8a1a9b2c77b Mon Sep 17 00:00:00 2001
From: Paul Gardner-Stephen <paul@servalproject.org>
Date: Sat, 20 Apr 2019 23:43:12 +0930
Subject: [PATCH] make cursor visible immediately after printing a character,
 but for only 1 frame, to match C64 KERNAL behaviour

---
 c64/kernal/blink_cursor.s | 13 +++++++++++++
 c64/kernal/chrout.s       |  5 ++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/c64/kernal/blink_cursor.s b/c64/kernal/blink_cursor.s
index 09aa3cc3..4dd8e55c 100644
--- a/c64/kernal/blink_cursor.s
+++ b/c64/kernal/blink_cursor.s
@@ -4,6 +4,19 @@
 	;; cursor_saved_character
 	;; cursor_is_visible
 	;; colour_under_cursor
+
+show_cursor:
+	;; Set cursor as though it had just finished the off phase,
+	;; so that the call to blink_cursor paints it
+	lda #$00
+	sta cursor_blink_countdown
+	sta cursor_is_visible
+	jsr blink_cursor
+	;; Then set the timeout to 1 frame, so that the cursor
+	;; blinks under key repeat conditions, like on the original KERNAL
+	lda #$01
+	sta cursor_blink_countdown
+	rts
 	
 blink_cursor:
 	;; Is the cursor enabled?
diff --git a/c64/kernal/chrout.s b/c64/kernal/chrout.s
index 479234b9..ff871bfe 100644
--- a/c64/kernal/chrout.s
+++ b/c64/kernal/chrout.s
@@ -136,7 +136,10 @@ chrout_l1:
 	bcc no_screen_advance_to_next_line
 	jmp screen_advance_to_next_line
 no_screen_advance_to_next_line:
-chrout_done:	
+chrout_done:
+	;; Make cursor immediately visible
+	jsr show_cursor
+	
 	;; Restore X and Y, set carry to mark success on exit
 	pla
 	tay