diff --git a/bin/fdisk.ini b/bin/fdisk.ini
index 8110946..4339fa8 100644
--- a/bin/fdisk.ini
+++ b/bin/fdisk.ini
@@ -16,6 +16,7 @@
 ; CHECKEXTRA={TRUE | FALSE}
 ; COLORS={0<=N<=127}
 ; DEL_ND_LOG={ON | OFF}
+; DLA={0 | 1 | 2}
 ; DRIVE=#-####-###-##
 ; FLAG_SECTOR={0 | 2<=N<=64 | 256}
 ; LBA_MARKER={ON | OFF}
@@ -64,6 +65,16 @@
 ;            TRUE
 ;         *  FALSE
 ;
+; DLA        Drive letter assignment method.
+;         *  0      auto dectect by operating system
+;            1      FreeDOS / Microsoft driver letter assignment
+;                     one primary per disk (active first), then
+;                     all extended sorted by disk and partition table,
+;                     then all remaining primaries by disk and partition table
+;            2      DR-DOS drive letter assignment
+;                     all primaries first sorted by disk and partition table,
+;                     then all logicals by disk and partition table
+;
 ; FLAG_SECTOR       Sector number where the flags will be located.  The 
 ;                     default is 2.   
 ;            0      Disables sector flagging function.
diff --git a/source/fdisk/Makefile b/source/fdisk/Makefile
index 6628d6d..62362ac 100644
--- a/source/fdisk/Makefile
+++ b/source/fdisk/Makefile
@@ -22,7 +22,7 @@ TOOL_CC     = wcc386
 
 CC       = wcc
 CFLAGS   = -q -0 -bt=dos -wx -we
-!ifdef __LINUX__
+!ifdef __UNIX__
 CFLAGS   += -i=$(%WATCOM)/h
 !endif
 
@@ -30,7 +30,7 @@ AS       = nasm
 ASFLAGS  = -t -f obj
 LD       = wlink
 LDFLAGS  =
-!ifdef __LINUX__
+!ifdef __UNIX__
 SEP=/
 CP = cp
 MV = mv
@@ -76,6 +76,8 @@ CFLAGS += -DSMART_MBR=1
 objs += smartmbr.obj
 !endif
 
+.erase
+
 all : fdisk.exe
 dist : ../../fdisk.zip
 dist-svardos: ../../fdisk.svp
diff --git a/source/fdisk/display.c b/source/fdisk/display.c
index c482710..1664472 100644
--- a/source/fdisk/display.c
+++ b/source/fdisk/display.c
@@ -67,6 +67,9 @@ void Display_Information( void )
          con_print( "FAT32" );
       }
 
+      con_set_cursor_xy( 68, 1 );
+      con_printf("DLA%u", flags.dla );
+
       if ( flags.use_ambr == TRUE ) {
          con_set_cursor_xy( 73, 1 );
          con_print( "AMBR" );
diff --git a/source/fdisk/fdiskio.c b/source/fdisk/fdiskio.c
index 3bba4d1..27b7382 100644
--- a/source/fdisk/fdiskio.c
+++ b/source/fdisk/fdiskio.c
@@ -489,6 +489,19 @@ void Process_Fdiskini_File( void )
                command_ok = TRUE;
             }
 
+            /* Check for the COLORS statement */
+            if ( 0 == stricmp( command_buffer, "DLA" ) ) {
+               number = atoi( setting_buffer );
+
+               if ( ( number >= 0 ) && ( number <= 2 ) ) {
+                  flags.dla = number;
+               }
+               else {
+                  goto parse_error;
+               }
+               command_ok = TRUE;
+            }
+
             /* Check for the DEL_ND_LOG statement */
             if ( 0 == stricmp( command_buffer, "DEL_ND_LOG" ) ) {
                if ( !bool_string_to_int( &flags.del_non_dos_log_drives,
diff --git a/source/fdisk/main.c b/source/fdisk/main.c
index 2e0849f..c956dd8 100644
--- a/source/fdisk/main.c
+++ b/source/fdisk/main.c
@@ -165,6 +165,15 @@ static int Get_Environment_Settings( char *environment[] )
          bool_string_to_int( &flags.del_non_dos_log_drives, setting_buffer );
       }
 
+      /* Check for drive letter ordering */
+      if ( 0 == strcmp( command_buffer, "FFD_DLA" ) ) {
+         number = atoi( setting_buffer );
+
+         if ( ( number >= 0 ) && ( number <= 2 ) ) {
+            flags.dla = number;
+         }
+      }
+
       /* Check for the FLAG_SECTOR statement */
       if ( 0 == strcmp( command_buffer, "FFD_FLAG_SECTOR" ) ) {
          number = atoi( setting_buffer );
@@ -247,6 +256,7 @@ static void InitOptions( char *environment[] )
 
    /* initialize flags, the ones not set here default to FALSE */
    flags.display_name_description_copyright = TRUE;
+   flags.dla = 0;    /* drive letter assignment based on OS */
    flags.drive_number = 128;
    flags.flag_sector = 2;
    flags.lba_marker = TRUE;
@@ -287,8 +297,18 @@ static void InitOptions( char *environment[] )
    if ( flags.version >= COMP_W95B ) {
       flags.fat32 = TRUE;
    }
+
+   if ( flags.dla == DLA_AUTO ) {
+      if ( os_oem == OEM_DRDOS ) {
+         flags.dla = DLA_DRDOS;
+      }
+      else {
+         flags.dla = DLA_MSDOS;
+      }
+   }
 }
 
+
 static void InitDisks( void )
 {
    /* Check for interrupt 0x13 extensions (If the proper version is set.) */
diff --git a/source/fdisk/main.h b/source/fdisk/main.h
index e4db4be..8c8129b 100644
--- a/source/fdisk/main.h
+++ b/source/fdisk/main.h
@@ -152,6 +152,7 @@ typedef struct flags_structure {
    int using_default_drive_number;
    int check_for_extra_cylinder;
    int do_not_pause_help_information;
+   int dla;
    int drive_number;
    int esc;
    int extended_options_flag;
diff --git a/source/fdisk/pdiskio.c b/source/fdisk/pdiskio.c
index c46b381..2b1197f 100644
--- a/source/fdisk/pdiskio.c
+++ b/source/fdisk/pdiskio.c
@@ -66,6 +66,7 @@ extern void Pause( void );
 
 int os_version = 0;
 int os_version_minor = 0;
+int os_oem = 0;
 int os_gui_running = 0;
 
 void Determine_DOS_Version( void )
@@ -75,9 +76,24 @@ void Determine_DOS_Version( void )
    /* check for DOS <5 */
    r.w.ax = 0x3000;
    intr( 0x21, &r );
-   if ( r.h.al < 5 ) {
-      os_version = r.h.al;
-      os_version_minor = r.h.ah;
+   os_version = r.h.al;
+   os_version_minor = r.h.ah;
+   os_oem = r.h.bh;
+
+   if ( os_oem == OEM_IBM ) {
+      /* Is it DR-DOS pretending to be PC-DOS? */
+      r.w.ax = 0x4452;
+      intr( 0x21, &r );
+      if ( !( r.w.flags & INTR_CF ) ) {
+         os_oem = OEM_DRDOS;
+      }
+   }
+   if ( os_oem == OEM_NOVELL ) {
+      /* treat Novell DR-DOS as all other DR-DOS versions */
+      os_oem = OEM_DRDOS;
+   }
+
+   if ( os_version < 5 ) {
       return;
    }
 
@@ -262,25 +278,45 @@ int Num_Ext_Part( Partition_Table *pDrive )
    return num_ext;
 }
 
+void dla_msdos(  int *cl  );
+void dla_drdos(  int *cl  );
+void dla_nondos( void );
+
 /* Determine drive letters */
 int Determine_Drive_Letters( void )
 /* Returns last used drive letter as ASCII number. */
 {
-   //  int active_found=FALSE;
    int current_letter = 'C';
-   //  int drive_found=FALSE;
-   int index = 0;
-   int non_dos_partition;
-   int non_dos_partition_counter;
-   int sub_index = 0;
-
-   int active_part_found[MAX_DISKS];
 
    Load_Brief_Partition_Table();
 
    /* Clear drive_lettering_buffer[8] [27] */
    memset( drive_lettering_buffer, 0, sizeof( drive_lettering_buffer ) );
 
+   if ( flags.dla == DLA_MSDOS ) {
+      dla_msdos( &current_letter );
+   }
+   else {
+      /* DR-DOS drive letter assignment puts all primaries of all drives 
+         first, in order of partition table, then all logicals, drive by
+         drive. */
+      dla_drdos( &current_letter );
+   }
+
+   /* assign numbers to non-DOS partitions */
+   dla_nondos();
+
+   return current_letter - 1;
+}
+
+
+void dla_msdos( int *cl )
+{
+   int current_letter = *cl;
+   int index = 0;
+   int sub_index = 0;
+   int active_part_found[MAX_DISKS];
+
    /* Set all active_part_found[] values to 0. */
    memset( active_part_found, 0, sizeof( active_part_found ) );
 
@@ -352,6 +388,60 @@ int Determine_Drive_Letters( void )
          }
       }
    }
+   *cl = current_letter;
+}
+
+
+void dla_drdos( int *cl )
+{
+   int current_letter = *cl;
+   int index = 0;
+   int sub_index = 0;
+
+   /* assign up to one drive letter to an active or non-active partition
+      per disk */
+   for ( index = 0; index < MAX_DISKS; index++ ) {
+      Partition_Table *pDrive = &part_table[index];
+      if ( !pDrive->usable ) {
+         continue;
+      }
+
+      /* find active partition for drive */
+      for ( sub_index = 0; sub_index < 4; sub_index++ ) {
+         if ( ( IsRecognizedFatPartition(
+                 brief_partition_table[index][sub_index] ) ) ) {
+            drive_lettering_buffer[index][sub_index] = current_letter;
+            current_letter++;
+         }
+      }
+   }
+
+   /* Next assign drive letters to applicable extended partitions... */
+   for ( index = 0; index < MAX_DISKS; index++ ) {
+      Partition_Table *pDrive = &part_table[index];
+      if ( !pDrive->usable ) {
+         continue;
+      }
+
+      for ( sub_index = 4; sub_index < 27; sub_index++ ) {
+         if ( IsRecognizedFatPartition(
+                 brief_partition_table[index][sub_index] ) ) {
+            drive_lettering_buffer[index][sub_index] = current_letter;
+            current_letter++;
+         }
+      }
+   }
+
+   *cl = current_letter;
+}
+
+
+void dla_nondos( void )
+{
+   int index = 0;
+   int sub_index = 0;
+   int non_dos_partition;
+   int non_dos_partition_counter;
 
    /* Find the Non-DOS Logical Drives in the Extended Partition Table */
    for ( index = 0; index < MAX_DISKS; index++ ) {
@@ -381,11 +471,10 @@ int Determine_Drive_Letters( void )
             }
          }
       }
-   }
-
-   return ( current_letter - 1 );
+   }   
 }
 
+
 void Clear_Partition( Partition *p )
 {
    memset( p, 0, sizeof( Partition ) );
diff --git a/source/fdisk/pdiskio.h b/source/fdisk/pdiskio.h
index fb528b0..1fd4584 100644
--- a/source/fdisk/pdiskio.h
+++ b/source/fdisk/pdiskio.h
@@ -12,8 +12,19 @@
 #define OS_WIN_ME  8
 #define OS_WIN_NT  32
 
+#define OEM_IBM     0x00
+#define OEM_DRDOS   0xee
+#define OEM_NOVELL  0xef
+#define OEM_FRERDOS 0xfd
+
+#define DLA_AUTO  0
+#define DLA_MSDOS 1
+#define DLA_DRDOS 2  /* all primary partitions first, then logicals */
+
 extern int os_version;
 extern int os_version_minor;
+extern int os_oem;
+
 extern int os_gui_running;
 
 /* Buffers */