From 9ff2dbb70ec858f71e4f80cf28a0a9826fc3d6da Mon Sep 17 00:00:00 2001
From: Greg Hewgill <greg@hewgill.com>
Date: Sat, 1 Oct 2011 08:18:16 +1300
Subject: [PATCH] add --pc switch for starting run at specific program counter

---
 applepy.py |  9 +++++++++
 cpu6502.py | 11 +++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/applepy.py b/applepy.py
index 5bb98bb..0ed7736 100644
--- a/applepy.py
+++ b/applepy.py
@@ -377,6 +377,10 @@ class Apple2:
             args.extend([
                 "--ram", options.ram,
             ])
+        if options.pc is not None:
+            args.extend([
+                "--pc", str(options.pc),
+            ])
         self.core = subprocess.Popen(args)
 
         rs, _, _ = select.select([listener], [], [], 2)
@@ -433,6 +437,7 @@ def usage():
     print >>sys.stderr, "    -c, --cassette Cassette wav file to load"
     print >>sys.stderr, "    -R, --rom      ROM file to use (default A2ROM.BIN)"
     print >>sys.stderr, "    -r, --ram      RAM file to load (default none)"
+    print >>sys.stderr, "    -p, --pc       Initial PC value"
     print >>sys.stderr, "    -q, --quiet    Quiet mode, no sounds (default sounds)"
     sys.exit(1)
 
@@ -443,6 +448,7 @@ def get_options():
             self.cassette = None
             self.rom = "A2ROM.BIN"
             self.ram = None
+            self.pc = None
             self.quiet = False
 
     options = Options()
@@ -458,6 +464,9 @@ def get_options():
             elif sys.argv[a] in ("-r", "--ram"):
                 a += 1
                 options.ram = sys.argv[a]
+            elif sys.argv[a] in ("-p", "--pc"):
+                a += 1
+                options.pc = int(sys.argv[a])
             elif sys.argv[a] in ("-q", "--quiet"):
                 options.quiet = True
             else:
diff --git a/cpu6502.py b/cpu6502.py
index 5fea0f4..c29c4cc 100644
--- a/cpu6502.py
+++ b/cpu6502.py
@@ -505,7 +505,7 @@ class CPU:
     STACK_PAGE = 0x100
     RESET_VECTOR = 0xFFFC
     
-    def __init__(self, memory):
+    def __init__(self, options, memory):
         self.memory = memory
 
         self.control_server = BaseHTTPServer.HTTPServer(("127.0.0.1", 6502), ControlHandlerFactory(self))
@@ -528,6 +528,8 @@ class CPU:
         
         self.setup_ops()
         self.reset()
+        if options.pc is not None:
+            self.program_counter = options.pc
         self.running = True
         self.quit = False
     
@@ -1176,6 +1178,7 @@ def usage():
     print >>sys.stderr, "Usage: cpu6502.py [options]"
     print >>sys.stderr
     print >>sys.stderr, "    -b, --bus      Bus port number"
+    print >>sys.stderr, "    -p, --pc       Initial PC value"
     print >>sys.stderr, "    -R, --rom      ROM file to use (default A2ROM.BIN)"
     print >>sys.stderr, "    -r, --ram      RAM file to load (default none)"
     sys.exit(1)
@@ -1187,6 +1190,7 @@ def get_options():
             self.rom = "A2ROM.BIN"
             self.ram = None
             self.bus = None
+            self.pc = None
 
     options = Options()
     a = 1
@@ -1195,6 +1199,9 @@ def get_options():
             if sys.argv[a] in ("-b", "--bus"):
                 a += 1
                 options.bus = int(sys.argv[a])
+            elif sys.argv[a] in ("-p", "--pc"):
+                a += 1
+                options.pc = int(sys.argv[a])
             elif sys.argv[a] in ("-R", "--rom"):
                 a += 1
                 options.rom = sys.argv[a]
@@ -1219,5 +1226,5 @@ if __name__ == "__main__":
 
     mem = Memory(options)
     
-    cpu = CPU(mem)
+    cpu = CPU(options, mem)
     cpu.run(options.bus)