From 95460f34da9f3c8d761076fb20e372da86adaba4 Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Wed, 27 Nov 2019 19:08:04 +0100
Subject: [PATCH] further improved JiffyDOS badline avoidance

---
 c64/kernal/iec/iec_jiffydos.s | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/c64/kernal/iec/iec_jiffydos.s b/c64/kernal/iec/iec_jiffydos.s
index e7154d62..ac2ca272 100644
--- a/c64/kernal/iec/iec_jiffydos.s
+++ b/c64/kernal/iec/iec_jiffydos.s
@@ -192,15 +192,18 @@ jiffydos_wait_line:
 	beq jiffydos_wait_line_done        // screen is disabled, no need to watch for badlines
 
 	// Avoid 2 lines before the badline, otherwise VIC will ruin the synchronization
-!:
-	sec
 	lda VIC_RASTER
+	cmp #$2E
+	bcc jiffydos_wait_line_done        // we are safe, border - lot of time till badline
+!:
+	lda VIC_RASTER                     // carry is definitely set here!
 	sbc VIC_SCROLY
 	and #$07                           // we want 8 lowest bits
 	cmp #$06
 	bcs !-
 
 jiffydos_wait_line_done:
+
 	rts