From f235dd6d7c4de97a732db4d7efe2fec220b78974 Mon Sep 17 00:00:00 2001
From: Aaron Culliney <devnull@deadc0de.org>
Date: Sun, 11 Nov 2018 08:00:43 -0800
Subject: [PATCH] Introduce some one-off memory fixes for poorly-written kracks

---
 src/misc.c |  1 +
 src/vm.c   | 28 +++++++++++++++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/misc.c b/src/misc.c
index a365922b..7ec44d26 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -41,6 +41,7 @@ CrashHandler_s *crashHandler = NULL;
 static void _init_common(void) {
     data_dir = STRDUP(CONFIG_DATADIR PATH_SEPARATOR PACKAGE_NAME);
     log_init();
+    srandom((unsigned int)time(NULL));
     LOG("Initializing common...");
 }
 
diff --git a/src/vm.c b/src/vm.c
index 61d658e0..8b1da949 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1090,13 +1090,39 @@ static void _initialize_apple_ii_memory(void) {
     }
 
     // Stripe words of main memory on machine reset ...
-    // NOTE: cracked version of J---- will lock up without this
+    // NOTE: cracked version of Joust will lock up without this
     for (unsigned int i = 0; i < 0xC000;) {
         apple_ii_64k[0][i++] = 0xFF;
         apple_ii_64k[0][i++] = 0xFF;
         i += 2;
     }
 
+#if !CPU_TRACING && !VIDEO_TRACING
+    // certain memory locations randomized at cold-boot ...
+    for (uint16_t addr = 0x0000; addr < 0xC000; addr += 0x200)
+    {
+        uint16_t word;
+
+        word = random();
+        apple_ii_64k[0][addr + 0x28] = (word >> 0) & 0xFF;
+        apple_ii_64k[0][addr + 0x29] = (word >> 8) & 0xFF;
+
+        word = random();
+        apple_ii_64k[0][addr + 0x68] = (word >> 0) & 0xFF;
+        apple_ii_64k[0][addr + 0x69] = (word >> 8) & 0xFF;
+    }
+
+    // memory initialization workarounds ...
+    {
+        // https://github.com/AppleWin/AppleWin/issues/206
+        // work around cold-booting bug in "Pooyan" which expects RNDL and RNDH to be non-zero
+        // "Dung Beetles, Ms. PacMan, Pooyan, Star Cruiser, Star Thief, Invas. Force.dsk"
+        uint16_t word = (uint16_t)random();
+        apple_ii_64k[0][0x4E] = 0x20 | ((word >> 0) & 0xFF);
+        apple_ii_64k[0][0x4F] = 0x20 | ((word >> 8) & 0xFF);
+    }
+#endif
+
     for (unsigned int i = 0; i < 8192; i++) {
         language_card[0][i] = language_card[1][i] = 0;
     }