From a25ad398e89eb9a7c39ec12627da1d04edf56f0b Mon Sep 17 00:00:00 2001
From: Rob McMullen <feedback@playermissile.com>
Date: Tue, 19 Dec 2017 14:59:28 -0800
Subject: [PATCH] Added -f flag to step through emulation at max possible speed
 (i.e. without the delay loop)

---
 6502-emu.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/6502-emu.c b/6502-emu.c
index 599fcc4..d91d159 100644
--- a/6502-emu.c
+++ b/6502-emu.c
@@ -19,7 +19,7 @@ void step_delay()
 	nanosleep(&req, &rem);
 }
 
-void run_cpu(long cycle_stop, int verbose, int mem_dump, int break_pc)
+void run_cpu(long cycle_stop, int verbose, int mem_dump, int break_pc, int fast)
 {
 	long cycles = 0;
 	int cycles_per_step = (CPU_FREQ / (ONE_SECOND / STEP_DURATION));
@@ -37,7 +37,7 @@ void run_cpu(long cycle_stop, int verbose, int mem_dump, int break_pc)
 				goto end;
 			}
 		}
-		step_delay(); // remove this for more speed
+		if (!fast) step_delay();
 	}
 end:
 	return;
@@ -70,7 +70,7 @@ int hextoint(char *str) {
 int main(int argc, char *argv[])
 {
 	int a, x, y, sp, sr, pc, load_addr;
-	int verbose, interactive, mem_dump, break_pc;
+	int verbose, interactive, mem_dump, break_pc, fast;
 	long cycles;
 	int opt;
 
@@ -80,13 +80,14 @@ int main(int argc, char *argv[])
 	cycles = 0;
 	load_addr = 0xC000;
 	break_pc = -1;
+	fast = 0;
 	a = 0;
 	x = 0;
 	y = 0;
 	sp = 0;
 	sr = 0;
 	pc = -RST_VEC;  // negative implies indirect
-	while ((opt = getopt(argc, argv, "vima:b:x:y:r:p:s:g:c:l:")) != -1) {
+	while ((opt = getopt(argc, argv, "vimfa:b:x:y:r:p:s:g:c:l:")) != -1) {
 		switch (opt) {
 		case 'v':
 			verbose = 1;
@@ -97,6 +98,9 @@ int main(int argc, char *argv[])
 		case 'm':
 			mem_dump = 1;
 			break;
+		case 'f':
+			fast = 1;
+			break;
 		case 'b':
 			break_pc = hextoint(optarg);
 			break;
@@ -147,7 +151,7 @@ int main(int argc, char *argv[])
 	init_uart();
 	
 	reset_cpu(a, x, y, sp, sr, pc);
-	run_cpu(cycles, verbose, mem_dump, break_pc);
+	run_cpu(cycles, verbose, mem_dump, break_pc, fast);
 	
 	return EXIT_SUCCESS;
 }