--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test_int_timing.c	Mon Jan 16 21:38:49 2017 -0800
@@ -0,0 +1,87 @@
+/*
+ Copyright 2017 Michael Pavone
+ This file is part of BlastEm.
+ BlastEm is free software distributed under the terms of the GNU General Public License version 3 or greater. See COPYING for full license text.
+*/
+#include <stdio.h>
+#include "vdp.h"
+
+int headless = 1;
+
+uint32_t render_map_color(uint8_t r, uint8_t g, uint8_t b)
+{
+	return 0;
+}
+
+uint16_t read_dma_value(uint32_t address)
+{
+	return 0;
+}
+
+
+int main(int argc, char **argv)
+{
+	vdp_context context;
+	int ret = 0;
+	init_vdp_context(&context, 0);
+	vdp_control_port_write(&context, 0x8000 | BIT_PAL_SEL);
+	vdp_control_port_write(&context, 0x8100 | BIT_DISP_EN | BIT_VINT_EN | BIT_MODE_5);
+	puts("Testing H32 Mode");
+	while (!(context.flags2 & FLAG2_VINT_PENDING))
+	{
+		vdp_run_context(&context, context.cycles + 1);
+	}
+	vdp_int_ack(&context);
+	uint32_t vint_cycle = vdp_next_vint(&context);
+	while (!(context.flags2 & FLAG2_VINT_PENDING))
+	{
+		vdp_run_context(&context, context.cycles + 1);
+		uint32_t vint_cycle2 = vdp_next_vint(&context);
+		if (vint_cycle2 != vint_cycle) {
+			printf("VINT Cycle changed from %d to %d @ line %d, slot %d\n", vint_cycle, vint_cycle2, context.vcounter, context.hslot);;
+			ret = 1;
+			vint_cycle = vint_cycle2;
+		}
+	}
+	vdp_int_ack(&context);
+	puts("Testing H40 Mode");
+	vdp_control_port_write(&context, 0x8C81);
+	while (!(context.flags2 & FLAG2_VINT_PENDING))
+	{
+		vdp_run_context(&context, context.cycles + 1);
+	}
+	vdp_int_ack(&context);
+	vint_cycle = vdp_next_vint(&context);
+	while (!(context.flags2 & FLAG2_VINT_PENDING))
+	{
+		vdp_run_context(&context, context.cycles + 1);
+		uint32_t vint_cycle2 = vdp_next_vint(&context);
+		if (vint_cycle2 != vint_cycle) {
+			printf("VINT Cycle changed from %d to %d @ line %d, slot %d\n", vint_cycle, vint_cycle2, context.vcounter, context.hslot);;
+			ret = 1;
+			vint_cycle = vint_cycle2;
+		}
+	}
+	vdp_int_ack(&context);
+	puts("Testing Mode 4");
+	vdp_control_port_write(&context, 0x8C00);
+	vdp_control_port_write(&context, 0x8100 | BIT_DISP_EN | BIT_VINT_EN);
+	while (!(context.flags2 & FLAG2_VINT_PENDING))
+	{
+		vdp_run_context(&context, context.cycles + 1);
+	}
+	context.flags2 &= ~FLAG2_VINT_PENDING;
+	vint_cycle = vdp_next_vint(&context);
+	while (!(context.flags2 & FLAG2_VINT_PENDING))
+	{
+		vdp_run_context(&context, context.cycles + 1);
+		uint32_t vint_cycle2 = vdp_next_vint(&context);
+		if (vint_cycle2 != vint_cycle) {
+			printf("VINT Cycle changed from %d to %d @ line %d, slot %d\n", vint_cycle, vint_cycle2, context.vcounter, context.hslot);;
+			ret = 1;
+			vint_cycle = vint_cycle2;
+		}
+	}
+	printf("Result: %s\n", ret ? "failure" : "success");
+	return ret;
+}
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