# HG changeset patch
# User Michael Pavone <pavone@retrodev.com>
# Date 1481775634 28800
# Node ID 87114df913ec021c2b3f28d1ff012d611f3f3c21
# Parent  fc125af5e4f18583b8fd8bc78e45a4485d3854c5
Fix Z80 interrupt pulse duration. Fixes inconsistent music playback speed in Sonic 2 introduced in 0.4.1

diff -r fc125af5e4f1 -r 87114df913ec genesis.c
--- a/genesis.c	Mon Dec 12 19:21:22 2016 -0800
+++ b/genesis.c	Wed Dec 14 20:20:34 2016 -0800
@@ -97,14 +97,13 @@
 #define dputs
 #endif
 
-#define Z80_VINT_DURATION 128
-
 void z80_next_int_pulse(z80_context * z_context)
 {
-		genesis_context * gen = z_context->system;
+	genesis_context * gen = z_context->system;
 	z_context->int_pulse_start = vdp_next_vint_z80(gen->vdp);
-	z_context->int_pulse_end = z_context->int_pulse_start + Z80_VINT_DURATION * MCLKS_PER_Z80;
-			}
+	//Notes in the Genesis Plus GX code suggest this is asserted for one line
+	z_context->int_pulse_end = z_context->int_pulse_start + MCLKS_LINE;
+}
 
 void sync_z80(z80_context * z_context, uint32_t mclks)
 {