Improve disk write support

README.md

@@ -81,7 +81,7 @@ Use it at your own risk!
 
 Kung Fu Flash will work with the PAL version of the Commodore 64 or Commodore 128. Support for the NTSC version is still considered experimental.
 
-Disk drive emulation is using kernal vectors and will not work with fast loaders or software that uses direct hardware access which a lot of games does. Currently REL files are not supported and there is only limited write support.
+Disk drive emulation is using kernal vectors and will not work with fast loaders or software that uses direct hardware access which a lot of games does. Currently REL files are not supported and only a subset of the Commodore DOS commands are supported.
 
 ## Thanks
 Kung Fu Flash was based on or uses other open source projects:

firmware/commands.h

@@ -52,15 +52,15 @@ typedef enum
 
     CMD_MOUNT_DISK,
     CMD_WAIT_RESET,     // Disable screen and wait for reset
-    CMD_WAIT_SYNC,
 
     // Disk commands
     CMD_NO_DRIVE = 0x10,
     CMD_DISK_ERROR,
     CMD_NOT_FOUND,
     CMD_END_OF_FILE,
 
-    // SYNC command
+    // SYNC commands
+    CMD_WAIT_SYNC = 0x50,
     CMD_SYNC = 0x55,
 
     REPLY_OK = 0x80,
@@ -83,11 +83,17 @@ typedef enum
     // Disk replies
     REPLY_LOAD = 0x90,
     REPLY_SAVE,
+
     REPLY_OPEN,
     REPLY_CLOSE,
+
     REPLY_TALK,
     REPLY_UNTALK,
-    REPLY_GET_BYTE,
+    REPLY_SEND_BYTE,
+
+    REPLY_LISTEN,
+    REPLY_UNLISTEN,
+    REPLY_RECEIVE_BYTE
 } COMMAND_TYPE;
 
 typedef enum