diff -Naur spediv_v0.2b/divide.c spediv_v0.2c/divide.c
--- spediv_v0.2b/divide.c	2005-09-02 11:11:53.000000000 +0200
+++ spediv_v0.2c/divide.c	2007-02-05 00:50:14.000000000 +0100
@@ -129,7 +129,8 @@
   int buffer_len;
 
   int cmd;		// pending command (read sector/write sector)
-
+  int nsec;
+  
 // IDE registers (Read/Write)
   int port_AF;	// chs/lba
   int port_B3;	// chs/lba
@@ -384,6 +385,7 @@
       if ( DISK.buffer_ptr < DISK.buffer_len ) {
         data = DISK.buffer[DISK.buffer_ptr];
         DISK.buffer_ptr++;
+        if (!(DISK.buffer_ptr&0x1FF)) DISK.port_AB--;
 
         // readed whole buffer?
         if (DISK.buffer_ptr >= DISK.buffer_len)
@@ -608,6 +610,7 @@
         DISK.buffer_ptr = 0;
         DISK.buffer_len = 0;
         DISK.cmd = DIVIDE_WRITE_BUFF;
+        DISK.nsec = 0;
         DISK.in_port_BF &= (STATUS_CLR_BSY & STATUS_CLR_DF & STATUS_CLR_ERR);
         DISK.in_port_BF |= (STATUS_SET_DRDY | STATUS_SET_DRQ);
         break;
@@ -635,7 +638,8 @@
       else
         lba = chs2lba(drive, (DISK.port_B7 << 8) | DISK.port_B3, DISK.port_BB & 0x0F, DISK.port_AF);
       
-      // write sector to disk
+      lba+=DISK.nsec;
+      // write n-th sector to disk
       tlba=lba;
       if (tlba < DISK.mbr.len) {
         DISK.mbr.ptr = lseek(DISK.mbr.fd, (tlba << 9), SEEK_SET);
@@ -653,11 +657,13 @@
       }
       DISK.buffer_len=0;
       DISK.port_AB--;
+      DISK.nsec++;
       lba++;
     }
     // we are done with writing?
     if (!DISK.port_AB) {
       DISK.cmd=0;
+      DISK.nsec=0;
       DISK.in_port_BF &= STATUS_CLR_DRQ;
     }
     break;