From 8db1146c5ded68b2d3356e19c3475b43a97de6f5 Mon Sep 17 00:00:00 2001
From: recompileorg <drichardson@recompile.org>
Date: Mon, 13 Apr 2020 05:57:49 -0400
Subject: [PATCH] Fixes #40 - Intellicart roms w/o A8

Detects Intellicart roms using a different method for files that don't begin with 0xA8
---
 src/cart.c | 74 ++++++++++++++++++++++++++++++++++++++----------------
 src/intv.c | 12 ++++-----
 2 files changed, 59 insertions(+), 27 deletions(-)

diff --git a/src/cart.c b/src/cart.c
index 4c10d5e..4da6512 100644
--- a/src/cart.c
+++ b/src/cart.c
@@ -16,9 +16,13 @@
 */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include "memory.h"
 #include "cart.h"
+#include "osd.h"
 
+int isIntellicart(void);
+int loadIntellicart(void);
 int isROM(void);
 int loadROM(void);
 int getLoadMethod(void);
@@ -65,33 +69,50 @@ int LoadCart(const char *path)
         if (ferror(fp))
         {
             printf("[ERROR] [FREEINTV] Cartridge load error indicator set\n");
+			return 0;
         }
         
-        if(isROM()) // intellicart format
+		char buffer[8] = {0,0,0,0,0,0,0,0};
+		itoa(size, buffer, 10);
+		OSD_drawText(8, 4, "SIZE:");
+		OSD_drawText(14, 4, buffer);
+
+        if(isIntellicart()) // intellicart format
         {
+			OSD_drawText(8, 4, "INTELLICART");
             printf("[INFO] [FREEINTV] Intellicart cartridge format detected\n");		
-            return loadROM();
+            return loadIntellicart();
         }
         else
         {
-            // check cartinfo database for load method
-            printf("[INFO] [FREEINTV] Intelllicart format not detected. Determining load method via database.\n");		
-            switch(getLoadMethod())
-            {
-                    case 0: load0(); break;
-                    case 1: load1(); break;
-                    case 2: load2(); break;
-                    case 3: load3(); break;
-                    case 4: load4(); break;
-                    case 5: load5(); break;
-                    case 6: load6(); break;
-                    case 7: load7(); break;
-                    case 8: load8(); break;
-                    case 9: load9(); break;
-                    default: printf("[INFO] [FREEINTV] No database match. Using default cartridge memory map.\n"); load0();
-            }
+			if(isROM())
+			{
+				OSD_drawText(8, 4, "INTELLICART");
+				OSD_drawText(8, 5, "MISSING A8!");
+				printf("[INFO] [FREEINTV] Possible Intellicart cartridge format detected\n");
+				return loadROM();
+			}
+			else
+			{
+				// check cartinfo database for load method
+				printf("[INFO] [FREEINTV] Raw ROM image. Determining load method via database.\n");		
+				switch(getLoadMethod())
+				{
+						case 0: load0(); break;
+						case 1: load1(); break;
+						case 2: load2(); break;
+						case 3: load3(); break;
+						case 4: load4(); break;
+						case 5: load5(); break;
+						case 6: load6(); break;
+						case 7: load7(); break;
+						case 8: load8(); break;
+						case 9: load9(); break;
+						default: printf("[INFO] [FREEINTV] No database match. Using default cartridge memory map.\n"); load0();
+				}
+			}
         }
-        return 1;
+        return 1; // loaded okay
 	}
     else
     {
@@ -120,13 +141,19 @@ void loadRange(int start, int stop)
 }
 
 // http://spatula-city.org/~im14u2c/intv/jzintv-1.0-beta3/doc/rom_fmt/IntellicartManual.booklet.pdf
-int isROM() // check for intellicart format rom
+int isIntellicart() // check for intellicart format rom
 {
 	// check magic number (used for intellicart baud rate detection)
 	return (data[0]==0xA8); 
 }
 
-int loadROM() // load intellicart format rom
+int isROM() // some Intellicart roms don't start with A8 for no apparent reason
+{
+	// the third byte should be the 1's compliment of the second byte
+	return data[1] == (data[2]^0xFF);
+}
+
+int loadIntellicart() // load intellicart format rom
 {
 	int start;
 	int stop;
@@ -149,6 +176,11 @@ int loadROM() // load intellicart format rom
 	return 1;
 }
 
+int loadROM() // load ROM formatted cart
+{
+	return loadIntellicart();
+}
+
 // http://atariage.com/forums/topic/203179-config-files-to-use-with-various-intellivision-titles/
 
 void load0() // default - handles majority of carts
diff --git a/src/intv.c b/src/intv.c
index cd0e2a7..ff2dabe 100644
--- a/src/intv.c
+++ b/src/intv.c
@@ -33,11 +33,11 @@ void LoadGame(const char* path) // load cart rom //
 {
 	if(LoadCart(path))
 	{
-		OSD_drawText(3, 3, "Load Cart: OKAY");
+		OSD_drawText(3, 3, "LOAD CART: OKAY");
 	}
 	else
 	{
-		OSD_drawText(3, 3, "Load Cart: FAIL");
+		OSD_drawText(3, 3, "LOAD CART: FAIL");
 	}
 }
 
@@ -56,12 +56,12 @@ void loadExec(const char* path)
 		}
 
 		fclose(fp);
-		OSD_drawText(3, 1, "Load EXEC: OKAY");
+		OSD_drawText(3, 1, "LOAD EXEC: OKAY");
 		printf("[INFO] [FREEINTV] Succeeded loading Executive BIOS from: %s\n", path);		
 	}
 	else
 	{
-		OSD_drawText(3, 1, "Load EXEC: FAIL");
+		OSD_drawText(3, 1, "LOAD EXEC: FAIL");
 		printf("[ERROR] [FREEINTV] Failed loading Executive BIOS from: %s\n", path);
 	}
 }
@@ -81,13 +81,13 @@ void loadGrom(const char* path)
 		}
 
 		fclose(fp);
-		OSD_drawText(3, 2, "Load GROM: OKAY");
+		OSD_drawText(3, 2, "LOAD GROM: OKAY");
 		printf("[INFO] [FREEINTV] Succeeded loading Graphics BIOS from: %s\n", path);
 		
 	}
 	else
 	{
-		OSD_drawText(3, 2, "Load GROM: FAIL");
+		OSD_drawText(3, 2, "LOAD GROM: FAIL");
 		printf("[ERROR] [FREEINTV] Failed loading Graphics BIOS from: %s\n", path);
 	}
 }