Version 10.5 - see readme.md for details

Author: wavemotion-dave

ColecoDS.nds

@@ -15,7 +15,7 @@ include $(DEVKITARM)/ds_rules
 
 export TARGET		:=	ColecoDS
 export TOPDIR		:=	$(CURDIR)
-export VERSION		:=  10.4b
+export VERSION		:=  10.5
 
 ICON 		:= -b $(CURDIR)/logo.bmp "ColecoDS $(VERSION);wavemotion-dave;https://github.com/wavemotion-dave/ColecoDS" 
 

Makefile

@@ -409,6 +409,13 @@ And then move the soundbank.h file to the arm9/sources directory
 
 Versions :
 -----------------------
+V10.5: 14-Mar-2025 by wavemotion-dave
+* Update to the Z80 core to improve emulation accuracy. This emulator now passes the ZEXALL test suite.
+* Added proper M1 wait states for the Colecovision, ADAM and MSX emulation for improved CPU handling.
+* A few optimized Z80 lookup-tables brings in some additional speed for both the DSi and DS-Lite/Phat.
+* Improved file loading so that it's more robust - ensuring a higher level of consistency in loading large files into memory.
+* Other minor cleanups as time permitted.
+
 V10.4: 10-Mar-2025 by wavemotion-dave
 * DSi now supports cart ROMs up to 4MB (4096K). Only a few MSX tech demos / games get anywhere near this.
 * New super-simplified Colecovision CPU driver that is used for most of the well-behaved Colecovision games to render them full speed on the older DS-Lite/Phat.

README.md

@@ -835,13 +835,8 @@ void adam_drive_update(u8 drive, u8 device, int cmd)
 // Read a .dsk or .ddp file from the SD card and place into memory
 void adam_drive_insert(u8 drive, char *filename)
 {
-    FILE *fp = fopen(filename, "rb");
-    if (fp)
-    {
-        AdamDrive[drive].image = ROM_Memory + ((drive*320)*1024);
-        AdamDrive[drive].imageSize = fread(AdamDrive[drive].image, 1, AdamDrive[drive].imageSizeMax, fp);
-        fclose(fp);
-    }
+    AdamDrive[drive].image = ROM_Memory + ((drive*320)*1024);
+    AdamDrive[drive].imageSize = ReadFileCarefully(filename, AdamDrive[drive].image, AdamDrive[drive].imageSizeMax, 0);
 }
 
 // Set the disk image for this drive bay back to NULL

arm9/gfx_data/pdev_bg0.png

@@ -76,33 +76,78 @@ u32 crcBasedOnFilename(const char *filename)
     return ~crc;
 }
 
+// -----------------------------------------------------------------------------------------------------------------
+// For disk and data pack games which may write back data, we don't want to base the CRC on the actual contents of
+// the media... so instead we'll just hash the filename as a CRC which is good enough to identify it in the future.
+// -----------------------------------------------------------------------------------------------------------------
+u32 getCRC32(u8 *buf, u32 size)
+{
+    u32 crc = 0xFFFFFFFF;
+
+    for (int i=0; i < size; i++)
+    {
+        crc = (crc >> 8) ^ crc32_table[(crc & 0xFF) ^ (u8)buf[i]]; 
+    }
+    
+    return ~crc;
+}
+
+
 // ------------------------------------------------------------------------------------
 // Read the file in and compute CRC... it's a bit slow but good enough and accurate!
+// When this routine finishes, the file will be read into ROM_Memory[]
 // ------------------------------------------------------------------------------------
-u8 file_crc_buffer[2048];
+extern u32 MAX_CART_SIZE;
+extern u8 *ROM_Memory;
+
 ITCM_CODE u32 getFileCrc(const char* filename)
 {
     extern u32 file_size;
-    u32 crc = 0xFFFFFFFF;
-    int bytesRead;
+    u32 crc1 = 0;
+    u32 crc2 = 1;
+    int bytesRead1 = 0;
+    int bytesRead2 = 1;
 
-    FILE* file = fopen(filename, "rb");
-    file_size=0;
-    while ((bytesRead = fread(file_crc_buffer, 1, sizeof(file_crc_buffer), file)) > 0)
+    // --------------------------------------------------------------------------------------------
+    // I've seen some rare issues with reading files from the SD card on a DSi so we're doing
+    // this slow and careful - we will read twice and ensure that we get the same CRC both 
+    // times in order for us to declare that this is a valid read. When we're done, the game
+    // ROM will be placed in the ROM_Memory[] and will be ready for use by the rest of the system.
+    // --------------------------------------------------------------------------------------------
+    do
     {
-        file_size += bytesRead;
-        for (int i=0; i < bytesRead; i++)
+        // Read #1
+        file_size = 0;
+        crc1 = 0xFFFFFFFF;
+        FILE* file = fopen(filename, "rb");
+        while ((bytesRead1 = fread(ROM_Memory, 1, (MAX_CART_SIZE * 1024), file)) > 0)
         {
-            crc = (crc >> 8) ^ crc32_table[(crc & 0xFF) ^ (u8)file_crc_buffer[i]]; 
+            file_size += bytesRead1;
+            for (int i=0; i < bytesRead1; i++)
+            {
+                crc1 = (crc1 >> 8) ^ crc32_table[(crc1 & 0xFF) ^ (u8)ROM_Memory[i]]; 
+            }
         }
-    }
-    fclose(file);
+        fclose(file);
+
+        // Read #2
+        crc2 = 0xFFFFFFFF;
+        FILE* file2 = fopen(filename, "rb");
+        while ((bytesRead2 = fread(ROM_Memory, 1, (MAX_CART_SIZE * 1024), file2)) > 0)
+        {
+            for (int i=0; i < bytesRead2; i++)
+            {
+                crc2 = (crc2 >> 8) ^ crc32_table[(crc2 & 0xFF) ^ (u8)ROM_Memory[i]]; 
+            }
+        }
+        fclose(file2);
+   } while (crc1 != crc2);
 
     // After we compute the size above... we check if this is a .dsk file and return CRC by name
     if (isDiskOrDataPack(filename))
     {
         return crcBasedOnFilename(filename);
     }
 
-    return ~crc;
+    return ~crc1;
 }

arm9/source/Adam.c

@@ -15,6 +15,7 @@
 #include <nds.h>
 
 u32 getFileCrc(const char* filename);
+u32 getCRC32(u8 *buf, u32 size);
 
 #endif