X-Git-Url: http://cloudbase.mooo.com/gitweb/avrcpm.git/blobdiff_plain/09fb1250adc484929f0e0ed9df942ad6560aacdf..b67feae671109efa5aa46d5712ab70b628010bbc:/dsk_fat16.asm

diff --git a/dsk_fat16.asm b/dsk_fat16.asm
index a0c648d..0a7510a 100644
--- a/dsk_fat16.asm
+++ b/dsk_fat16.asm
@@ -1,6 +1,8 @@
 ;    Various functions for the Interaction with the FAT16 Filesystem
 ;
 ;    Copyright (C) 2010 Frank Zoll
+;    Copyright (C) 2010 Sprite_tm
+;    Copyright (C) 2010 Leo C.
 ;
 ;    This file is part of avrcpm.
 ;
@@ -20,65 +22,84 @@
 ;    $Id$
 ;
 
-; ===========================================================================
+; ============================================================================
 ; Prelimitary !
 ; °°°°°°°°°°°°°
 ; Size of a Sector is fixed to 512 Bytes by Base - MMC Driver implementation
 ; The Functions below therefore assume a fixed Size of 512 Bytes per Sector.
-; ===========================================================================
+; ============================================================================
 
 #if FAT16_SUPPORT
 
 
-;-------------------------------- Defines for FAT16 Structures
+; ############################################################################ 
+;                       	Defines for FAT16 Structures
+; ############################################################################ 
+
 #define PARTID_FAT16 0x0E
-
-;#define FAT16_BSO_SECSIZE	0x0b		; BootSectorOffset to Sectorsize Word
-#define FAT16_BSO_CLUSTSZ   0x0d        ; BootSectorOffset to Clustersize Byte
-#define FAT16_BSO_RESSECT   0x0e		; BootSectorOffset to Number of Reserved Sectors
-#define FAT16_BSO_VOLPTR    0x1c        ; BootSectorOffset to First VolumeSector
-#define FAT16_BSO_SECPERFAT 0x16        ; BootSectorOffset to Number of Sectors per Fat
-#define FAT16_BSO_NUMFATCP  0x10		; BootSectorOffset to Ammount of FAT Copys
-#define FAT16_BSO_NUMDIRENT 0x11		; BootSectorOffset to Max. Root Dir. Entrys
-
-;-------------------------------- Start of Data Segment
-
+
+/*These are the Offsets to the Variables within the Bootsector of a FAT16
+  Partition.
+ */
+;#define FAT16_BSO_SECSIZE	0x0b	; Offset to Sectorsize Word
+#define FAT16_BSO_CLUSTSZ   	0x0d    ; Offset to Clustersize Byte
+#define FAT16_BSO_RESSECT   	0x0e	; Offset to Number of Reserved Sectors
+#define FAT16_BSO_VOLPTR    	0x1c    ; Offset to First VolumeSector
+#define FAT16_BSO_SECPERFAT 	0x16    ; Offset to Number of Sectors per Fat
+#define FAT16_BSO_NUMFATCP  	0x10	; Offset to Ammount of FAT Copys
+#define FAT16_BSO_NUMDIRENT 	0x11	; Offset to Max. Root Dir. Entrys
+#define	FAT16_FIRST_IMAGENAME	'A'	; First letter of filename to search 
+#define FAT16_LAST_IMAGENAME    'Z'	; Last letter of filename to search 
+
+; ############################################################################ 
+; 				Start of Data Segment
+; ############################################################################ 
 	.dseg
 
-fat_partfound:   .byte   1   ; (0= no fat partition found 1=found partition)
-fat_parttbl: 	 .byte	 8	 ; first fat16 partition entry (start sector, sector count)
-;fat_sectorsize:  .byte   2   ; size of sector in bytes
-fat_clustersize: .byte   1   ; sectors per cluster
-fat_ressectors:  .byte   2   ; number of reserved sectors
-fat_secperfat:   .byte   2   ; number of sectors per fat
-fat_numfatcp:    .byte   1   ; Number of FAT Copies
-fat_numdirentrys:.byte   2   ; Max. ammount of Directory Entrys within Rootdirektory
-fat_ptr2fat:     .byte   4   ; pointer to the first fat sector
-fat_ptr2dir:     .byte   4   ; pointer to the first root directory sector
-fat_ptr2dat:     .byte   4   ; pointer to the first data sector
-
-fat_last_dsk:	  .byte	 1   ; number of disk with entry in cache
-fat_log_clust:	  .byte	 2	 ; last searched logical cluster
-fat_clust_offset: .byte	 1   ; offset within the cluster
-fat_clust_ptr:	  .byte	 4;  ; sector of last real cluster
-; ------------------------------- Start of Code Segment
+fat_partfound:   .byte   1	; (partition: 0= no found 1=found )
+fat_parttbl: 	 .byte	 8	; first fat16 partition entry 
+				; (start sector, sector count)
+;fat_sectorsize:  .byte   2	; size of sector in bytes
+fat_clustersize: .byte   1	; sectors per cluster
+fat_ressectors:  .byte   2	; number of reserved sectors
+fat_secperfat:   .byte   2	; number of sectors per fat
+fat_numfatcp:    .byte   1	; number of FAT Copies
+fat_numdirentrys:.byte   2	; Max. num. of entrys within Rootdirektory
+fat_ptr2fat:     .byte   4	; pointer to the first fat sector
+fat_ptr2dir:     .byte   4	; pointer to the first root directory sector
+fat_ptr2dat:     .byte   4	; pointer to the first data sector
+
+/*These variables define a cache that holds the last Cluster and Sector
+  thats been searched vor. To save some of the valuabe SRAM- Space these
+  variables also are used as temporary variables by the function 
+  fat_scan_partition.
+  */
+fat_last_dsk:	  .byte	 1	; number of disk with entry in cache
+fat_log_clust:	  .byte	 2	; last searched logical cluster
+fat_clust_offset: .byte	 1	; offset within the cluster
+fat_clust_ptr:	  .byte	 4;	; sector of last real cluster
+
+
+; ############################################################################ 
+; 				Start of Code Segment
+; ############################################################################ 
 	.cseg
 
-; ====================================================================
-; Function: Does a Disk read/write operation
-; ====================================================================
+; ============================================================================
+; Function: Initialize internal FAT-Partition Variables
+; ============================================================================
 ; Parameters
-; --------------------------------------------------------------------
-; Registers  : none
-; Variables  : [r] seekdsk		Number of Disk to Read
-;			   [r] seeksec		Sector to read
-;              [r] seektrk		Track  to read
-; --------------------------------------------------------------------
-; Description:
-; ====================================================================
+; ----------------------------------------------------------------------------
+; Registers  :	none
+; Variables  :	[out]	fat_parttabl
+; ----------------------------------------------------------------------------
+; Description:
+; This Routine initializes the internal Variables, that point to the
+; first Found FAT16 Partition.
+; ============================================================================
 fat_init_partitiontable:
 
-	sts fat_partfound,_0
+	sts 	fat_partfound,_0
 
 	ldiw	y,fat_parttbl
 	st	y+,_0
@@ -89,26 +110,46 @@ fat_init_partitiontable:
 	st	y+,_0
 	st	y+,_0
 	st	y+,_0
+	ret
+
+; ============================================================================
+; Function: Resets the Cache
+; ============================================================================
+; Parameters
+; ----------------------------------------------------------------------------
+; Registers  :	none
+; Variables  :	[out]	fat_log_clust
+;		[out]	fat_last_dsk
+; ----------------------------------------------------------------------------
+; Description:
+; This Routine resets the internal Cache- Variables. After reset, the
+; next read or write Command will initialize a scan of the FAT of
+; the FAT16-Partition for the given sector.
+; ============================================================================
+fat_reset_cache:
+	push	yl
 	ldi	yl,0xFF
-	sts fat_log_clust  ,yl
+	sts 	fat_log_clust  ,yl
 	sts	fat_log_clust+1,yl
 	sts	fat_last_dsk   ,yl
+	pop	yl
 	ret
 
-; ====================================================================
-; Function: Add's a FAT16 Partition for later Scanning
-; ====================================================================
+; ============================================================================
+; Function: Saves FAT16 Partitiondata for later Scanning
+; ============================================================================
 ; Parameters
-; --------------------------------------------------------------------
-; Registers  : 
-; Variables  : 
-; --------------------------------------------------------------------
+; ----------------------------------------------------------------------------
+; Registers  :	[in]	z		Pointer to the Partitondata
+; Variables  :	[out]	fat_partfound	Boolean for "Partition found"
+;		[out]	fat_parttbl	Pointer to Partitiontable
+; ----------------------------------------------------------------------------
 ; Description:
-; This funktion sets the internal Variables to set Start and Size
+; This funktion sets the internal Variables to the Start and Size
 ; of a given FAT16 Paritition. This Information will be used for a
 ; later scanning of the Partition. See Function "fat_scan_partition"
 ; for more information. 
-; ====================================================================
+; ============================================================================
 fat_add_partition:
 	
 .if FAT16_DEBUG > 0
@@ -128,39 +169,39 @@ fat_add_partition:
 ;   save data from first fat16 partition
 	ldiw	y,fat_parttbl
 
-	ldd		temp,z+PART_START
-	st		y+,temp
-	ldd		temp,z+PART_START+1
-	st		y+,temp
-	ldd		temp,z+PART_START+2
-	st		y+,temp
-	ldd		temp,z+PART_START+3
-	st		y+,temp
+	ldd	temp,z+PART_START
+	st	y+,temp
+	ldd	temp,z+PART_START+1
+	st	y+,temp
+	ldd	temp,z+PART_START+2
+	st	y+,temp
+	ldd	temp,z+PART_START+3
+	st	y+,temp
 	
-	ldd		temp,z+PART_SIZE
-	st		y+,temp
-	ldd		temp,z+PART_SIZE+1
-	st		y+,temp
-	ldd		temp,z+PART_SIZE+2
-	st		y+,temp
-	ldd		temp,z+PART_SIZE+3
-	st		y+,temp
+	ldd	temp,z+PART_SIZE
+	st	y+,temp
+	ldd	temp,z+PART_SIZE+1
+	st	y+,temp
+	ldd	temp,z+PART_SIZE+2
+	st	y+,temp
+	ldd	temp,z+PART_SIZE+3
+	st	y+,temp
 
 
 ;   reload variables from stack
-	pop	 	yh
+	pop	yh
 	pop 	yl
 
 	ret
 
-; --------------------------------------------------------------------------- 
+; ============================================================================
 ; Read and Scann a FAT16 Partition for Imagedatefiles 
-; --------------------------------------------------------------------------- 
+; ============================================================================
+; Registers	: none
+; Variables	: none
+; ----------------------------------------------------------------------------
 ; This Routine reads the Bootblock and scanns it for a Diskimage
-; Input Registers  : none
-; Output Registers : none
-; Changes Variables: none
-; --------------------------------------------------------------------------- 
+; ============================================================================
 
 
 fat_scan_partition:
@@ -171,7 +212,7 @@ fat_scan_partition:
 .endif
 
 ; Check if a FAT16 Partition was realy found
-	lds		yl,fat_partfound
+	lds	yl,fat_partfound
 	cpi 	yl,1	
 	brne	fat_scan_error 
 
@@ -182,8 +223,8 @@ fat_scan_partition:
 .endif
 
 ; Check for free Entrys in Partition table
-	lds		yl,ndisks
-	cpi		yl,MAXDISKS
+	lds	yl,ndisks
+	cpi	yl,MAXDISKS
 	breq	fat_scan_error
 
 .if FAT16_DEBUG > 0
@@ -193,19 +234,19 @@ fat_scan_partition:
 
 ; Scan partition start
 	ldiw	z,fat_parttbl	
-	ldd		xl,z+0		
-	ldd		xh,z+1
-	ldd		yl,z+2
-	ldd		yh,z+3
+	ldd	xl,z+0		
+	ldd	xh,z+1
+	ldd	yl,z+2
+	ldd	yh,z+3
 
 ; Load first sector from Partition
 	rcall	mmcReadSect
-	tst	    temp
+	tst	temp
 	breq	fat_bootblock_check
 
 ; Read error: Block not found
 fat_scan_error:
-	clr temp
+	clr	temp
 	ret
 
 fat_bootblock_check:
@@ -215,7 +256,7 @@ fat_bootblock_check:
 	printnewline
 .endif
 
-; -> Size of Sectors fixed at 512 Bytes
+; Not needed / used by now because size of Sectors fixed at 512 Bytes
 ;   Get ammount of Bytes per Sector
 ;	ldiw	z,hostbuf+FAT16_BSO_SECSIZE
 ;	ldiw	y,fat_sectorsize
@@ -230,9 +271,9 @@ fat_bootblock_check:
 ;	printnewline
 ;.endif
 
-;   Anzahl der Sectoren pro Cluster lesen
+;   	get sectors per cluster from bootblock
 	ldiw	z,hostbuf+FAT16_BSO_CLUSTSZ
-	ld		temp,z
+	ld	temp,z
 	sts     fat_clustersize,temp
 
 .if FAT16_DEBUG > 0
@@ -241,12 +282,12 @@ fat_bootblock_check:
 	printnewline
 .endif
 
-;   Anzahl der reservierten Sectoren
+;	get num of reseved sectors from bootblock
 	ldiw	z,hostbuf+FAT16_BSO_RESSECT
-	ld		temp,z+
-	sts     fat_ressectors,temp			; low byte
-	ld		temp2,z
-	sts		fat_ressectors+1,temp2		; high byte
+	ld	temp,z+
+	sts     fat_ressectors,temp		; low byte
+	ld	temp2,z
+	sts	fat_ressectors+1,temp2		; high byte
 
 .if FAT16_DEBUG > 0
 	printstring "Reserved Sectors__: ",0
@@ -254,12 +295,12 @@ fat_bootblock_check:
 	printnewline
 .endif
 
-;   Anzahl der Sectoren pro FAT
+;	get num of sectors per FAT-Table from bootblock
 	ldiw	z,hostbuf+FAT16_BSO_SECPERFAT
-	ld		temp,z+
-	sts     fat_secperfat,temp			; low byte
-	ld		temp2,z
-	sts		fat_secperfat+1,temp2		; high byte
+	ld	temp,z+
+	sts     fat_secperfat,temp		; low byte
+	ld	temp2,z
+	sts	fat_secperfat+1,temp2		; high byte
 
 .if FAT16_DEBUG > 0
 	printstring "Sectors per FAT__: ",0
@@ -267,10 +308,10 @@ fat_bootblock_check:
 	printnewline
 .endif
 
-;   Anzahl der FAT kopien
+;   	get num of FAT Tables from bootblock
 	ldiw	z,hostbuf+FAT16_BSO_NUMFATCP
-	ld		temp,z
-	sts     fat_numfatcp,temp			; low byte
+	ld	temp,z
+	sts     fat_numfatcp,temp		; low byte
 
 .if FAT16_DEBUG > 0
 	printstring "Ammount of FAT copies: ",0
@@ -278,12 +319,12 @@ fat_bootblock_check:
 	printnewline
 .endif
 
-;   Max. Anzahl der Dir. Enträge im Root Verz.
+;	get max num of entrys in root direktory from bootblock
 	ldiw	z,hostbuf+FAT16_BSO_NUMDIRENT
-	ld		temp,z+
-	sts     fat_numdirentrys,temp			; low byte
-	ld		temp2,z
-	sts		fat_numdirentrys+1,temp2		; high byte
+	ld	temp,z+
+	sts     fat_numdirentrys,temp		; low byte
+	ld	temp2,z
+	sts	fat_numdirentrys+1,temp2	; high byte
 
 .if FAT16_DEBUG > 0
 	printstring "Max. entrys in Rootdir.: ",0
@@ -291,95 +332,95 @@ fat_bootblock_check:
 	printnewline
 .endif
 
-; Print begin of Volume
+; 	Print begin of Volume
 .if FAT16_DEBUG > 1
 
 	ldiw	z,fat_parttbl	
-	ldd		xl,z+0		
-	ldd		xh,z+1
-	ldd		yl,z+2
-	ldd		yh,z+3
+	ldd	xl,z+0		
+	ldd	xh,z+1
+	ldd	yl,z+2
+	ldd	yh,z+3
 
 	printstring "Begin of Volume at: ",0
-	mov		temp ,yl
-	mov		temp2,yh
-	rcall printhexw
-	mov		temp ,xl
-	mov		temp2,xh
-	rcall printhexw
+	mov	temp ,yl
+	mov	temp2,yh
+	rcall	printhexw
+	mov	temp ,xl
+	mov	temp2,xh
+	rcall	printhexw
 	printnewline
 .endif
 
-; Calculate begin of FAT within the Volume
-	lds		temp ,fat_ressectors
-	lds		temp2,fat_ressectors+1
+; 	Calculate begin of FAT within the Volume
+	lds	temp ,fat_ressectors
+	lds	temp2,fat_ressectors+1
 
 	ldiw	z,fat_parttbl	
-	ldd		xl,z+0		
-	ldd		xh,z+1
-	ldd		yl,z+2
-	ldd		yh,z+3
+	ldd	xl,z+0		
+	ldd	xh,z+1
+	ldd	yl,z+2
+	ldd	yh,z+3
 
-	add		xl,temp
+	add	xl,temp
 	adc 	xh,temp2
-	adc		yl,_0
-	adc		yh,_0
+	adc	yl,_0
+	adc	yh,_0
 
-	sts		fat_ptr2fat  ,xl
-	sts		fat_ptr2fat+1,xh
-	sts		fat_ptr2fat+2,yl
-	sts		fat_ptr2fat+3,yh
+	sts	fat_ptr2fat  ,xl
+	sts	fat_ptr2fat+1,xh
+	sts	fat_ptr2fat+2,yl
+	sts	fat_ptr2fat+3,yh
 
 .if FAT16_DEBUG > 1
 	printstring "Begin of FAT at___: ",0
-	mov		temp ,yl
-	mov		temp2,yh
-	rcall printhexw
-	mov		temp ,xl
-	mov		temp2,xh
-	rcall printhexw
+	mov	temp ,yl
+	mov	temp2,yh
+	rcall	printhexw
+	mov	temp ,xl
+	mov	temp2,xh
+	rcall	printhexw
 	printnewline
 .endif
 
 ; Calculate begin of Root- Directory within the Volume
 	ldiw	z,fat_ptr2fat
-	ldd		xl,z+0
-	ldd		xh,z+1
-	ldd		yl,z+2
-	ldd		yh,z+3
+	ldd	xl,z+0
+	ldd	xh,z+1
+	ldd	yl,z+2
+	ldd	yh,z+3
 
-	lds		temp ,fat_secperfat
-	lds		temp2,fat_secperfat+1
-	lds		temp3,fat_numfatcp
+	lds	temp ,fat_secperfat
+	lds	temp2,fat_secperfat+1
+	lds	temp3,fat_numfatcp
 
 fat_calc_dp_loop:
-	cp 		temp3,_0
+	cp 	temp3,_0
 	breq	fat_calc_dp_lend
 
-	add		xl,temp
-	adc		xh,temp2
-	adc		yl,_0
-	adc		yh,_0
+	add	xl,temp
+	adc	xh,temp2
+	adc	yl,_0
+	adc	yh,_0
 
-	dec		temp3
+	dec	temp3
 
-	jmp		fat_calc_dp_loop
+	jmp	fat_calc_dp_loop
 fat_calc_dp_lend:
 
-	sts		fat_ptr2dir  ,xl
-	sts		fat_ptr2dir+1,xh
-	sts		fat_ptr2dir+2,yl
-	sts		fat_ptr2dir+3,yh
+	sts	fat_ptr2dir  ,xl
+	sts	fat_ptr2dir+1,xh
+	sts	fat_ptr2dir+2,yl
+	sts	fat_ptr2dir+3,yh
 
 
 .if FAT16_DEBUG > 1
 	printstring "Begin of DIR at___: ",0
-	mov		temp ,yl
-	mov		temp2,yh
-	rcall printhexw
-	mov		temp ,xl
-	mov		temp2,xh
-	rcall printhexw
+	mov	temp ,yl
+	mov	temp2,yh
+	rcall	printhexw
+	mov	temp ,xl
+	mov	temp2,xh
+	rcall	printhexw
 	printnewline
 .endif
 
@@ -388,123 +429,214 @@ fat_calc_dp_lend:
 
 ; Sectorsize is fixed at 512 Bytes, makes 16 Entrys per Sektor
 
-	lds     zl,fat_numdirentrys			; low byte
-	lds		zh,fat_numdirentrys+1		; high byte
+	lds     zl,fat_numdirentrys		; low byte
+	lds	zh,fat_numdirentrys+1		; high byte
 
 ;   Num. Direntrys / 16
-	lsr		zh
-	ror		zl
-	lsr		zh
-	ror		zl
-	lsr		zh
-	ror		zl
-	lsr		zh
-	ror		zl
-
-	lds		xl,fat_ptr2dir
-	lds		xh,fat_ptr2dir+1
-	lds		yl,fat_ptr2dir+2
-	lds		yh,fat_ptr2dir+3
-
-	add		xl,zl
-	adc		xh,zh
-	adc		yl,_0
-	adc		yh,_0
-
-	sts		fat_ptr2dat  ,xl
-	sts		fat_ptr2dat+1,xh
-	sts		fat_ptr2dat+2,yl
-	sts		fat_ptr2dat+3,yh
+	lsr	zh
+	ror	zl
+	lsr	zh
+	ror	zl
+	lsr	zh
+	ror	zl
+	lsr	zh
+	ror	zl
+
+	lds	xl,fat_ptr2dir
+	lds	xh,fat_ptr2dir+1
+	lds	yl,fat_ptr2dir+2
+	lds	yh,fat_ptr2dir+3
+
+	add	xl,zl
+	adc	xh,zh
+	adc	yl,_0
+	adc	yh,_0
+
+	sts	fat_ptr2dat  ,xl
+	sts	fat_ptr2dat+1,xh
+	sts	fat_ptr2dat+2,yl
+	sts	fat_ptr2dat+3,yh
 
 .if FAT16_DEBUG > 1
 	printstring "Begin of Data at__: ",0
-	mov		temp ,yl
-	mov		temp2,yh
-	rcall printhexw
-	mov		temp ,xl
-	mov		temp2,xh
-	rcall printhexw
+	mov	temp ,yl
+	mov	temp2,yh
+	rcall	printhexw
+	mov	temp ,xl
+	mov	temp2,xh
+	rcall	printhexw
 	printnewline
 .endif
 
 ; Here Starts the Scann of the Directory for valid image Files.
 
-	lds		xl,fat_ptr2dir
-	lds		xh,fat_ptr2dir+1
-	lds		yl,fat_ptr2dir+2
-	lds		yh,fat_ptr2dir+3
-
-;  Load first sector from Directory
+;	Init Image-Namecounter
+	ldi	temp,FAT16_FIRST_IMAGENAME
+	sts	fat_last_dsk,temp
+
+fat_scan_for_next_image:
+
+;	Init Offset into Directory-Sectors
+	ldi	temp,0
+	sts	fat_clust_offset,temp
+
+;	Init counter for number of entry left to scan
+	lds	temp,fat_numdirentrys
+	sts	fat_log_clust  ,temp
+
+	lds	temp,fat_numdirentrys+1
+	sts	fat_log_clust+1,temp
+
+fat_next_sector_loop:
+;   Get a Pointer to the first Directory sector
+	lds	xl,fat_ptr2dir
+	lds	xh,fat_ptr2dir+1
+	lds	yl,fat_ptr2dir+2
+	lds	yh,fat_ptr2dir+3
+
+;	Add actual offset
+	lds	temp,fat_clust_offset
+	add	xl,temp
+	adc	xh,_0
+	adc	yl,_0
+	adc	yh,_0
+
+;  Load sector from Directory
 	call	mmcReadSect
-	tst	    temp
+	tst	temp
 	breq	fat_look_for_images
 
 ; Read error: Block not found
-	clr temp
+	clr	temp
 	ret
 
 ; Looks at a read directory block for image entrys
 fat_look_for_images:
 	
 	ldiw	z,hostbuf
-	ldi		temp2,0
+	ldi	temp2,0
 
 fat_look_for_loop:	
 	ldd 	temp,z+0
-	cpi		temp,'C'
+	cpi	temp,'C'
 	brne	fat_look_not_ok
 	
-	ldd		temp,z+1
-	cpi		temp,'P'
+	ldd	temp,z+1
+	cpi	temp,'P'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+2
-	cpi		temp,'M'
+	ldd	temp,z+2
+	cpi	temp,'M'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+3
-	cpi		temp,'D'
+	ldd	temp,z+3
+	cpi	temp,'D'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+4
-	cpi		temp,'S'
+	ldd	temp,z+4
+	cpi	temp,'S'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+5
-	cpi		temp,'K'
+	ldd	temp,z+5
+	cpi	temp,'K'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+6
-	cpi		temp,'_'
+	ldd	temp,z+6
+	cpi	temp,'_'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+8
-	cpi		temp,'I'
+	lds	temp3,fat_last_dsk	; Get actual Diskname (A to Z)
+	ldd	temp,z+7
+	cp	temp,temp3
+	brne	fat_look_not_ok
+
+	ldd	temp,z+8
+	cpi	temp,'I'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+9
-	cpi		temp,'M'
+	ldd	temp,z+9
+	cpi	temp,'M'
 	brne	fat_look_not_ok
 
-	ldd		temp,z+10
-	cpi		temp,'G'
+	ldd	temp,z+10
+	cpi	temp,'G'
 	brne	fat_look_not_ok
 
-	jmp		fat_store_new_entry
-
+	sts	fat_clust_ptr  ,zl
+	sts	fat_clust_ptr+1,zh
+	sts	fat_clust_ptr+2,temp2
+	jmp	fat_store_new_entry
+
+fat_scan_for_more:
+
+
+.if FAT16_DEBUG > 1
+	printstring "At:Scann for more ",0
+	printnewline
+.endif
+
+	lds	zl   ,fat_clust_ptr
+	lds	zh   ,fat_clust_ptr+1
+	lds	temp2,fat_clust_ptr+2
 fat_look_not_ok:
 	
-	//ldi		temp,32
-	addiw	z,32			
-
-	inc		temp2
-	cpi		temp2,16				; max entrys/sector
+.if FAT16_DEBUG > 1
+	printstring "+",0
+.endif
+	
+	adiw	z,32
+
+	inc	temp2
+	cpi	temp2,16				; max entrys/sector
 	breq	fat_scan_next_sector
 	jmp 	fat_look_for_loop
 
 fat_scan_next_sector:
 
-	ret
+.if FAT16_DEBUG > 1
+	printstring "At:Scan next Sector",0
+	printnewline
+.endif
+	
+	lds	temp3, fat_log_clust
+	lds	temp4, fat_log_clust+1
+
+	sub	temp3,temp2
+	sbc	temp4,_0
+
+	sts	fat_log_clust,temp3
+	sts	fat_log_clust+1,temp4
+	
+	cp	temp3,_0
+	cpc	temp4,_0
+	breq	fat_scan_at_end	
+
+	lds	temp,fat_clust_offset
+	inc	temp
+	sts	fat_clust_offset,temp
+
+	rjmp	fat_next_sector_loop
+
+fat_scan_at_end:
+
+.if FAT16_DEBUG > 1
+	printstring "At:Scan at end",0
+	printnewline
+.endif
+
+	lds	temp,fat_last_dsk
+	inc	temp
+	sts	fat_last_dsk,temp
+
+	ldi	temp2,FAT16_LAST_IMAGENAME
+	cp	temp,temp2
+	brge	fat_scaned_last_disk
+
+	rjmp	fat_scan_for_next_image
+
+fat_scaned_last_disk:
+
+	rjmp	fat_scan_end
 
 
 ;	Create new Partition Entry
@@ -512,36 +644,52 @@ fat_store_new_entry:
 
 ;   Found a valid image
 .if FAT16_DEBUG > 1
-	printstring "Found a valid Image ! ",0
+	printstring "Found a valid Image ! Z=",0
+	mov	temp ,zl
+	mov	temp2,zh
+	rcall	printhexw
 	printnewline
 .endif
 
 	ldiw	y,hostparttbl
-	lds		temp,ndisks
+	lds	temp,ndisks
 
 fat_look_store_loop:
-	cp		temp,_0
+	cp	temp,_0
 	breq	fat_look_store
 
 	adiw	y,PARTENTRY_SIZE
-	dec		temp
-	jmp		fat_look_store_loop
+	dec	temp
+	jmp	fat_look_store_loop
 
 fat_look_store:
 ;   Set Type of Partition to FAT16- Fileimage
-	ldi temp,dskType_FAT
+	ldi 	temp,dskType_FAT
 	st	y+,temp
 
+.if FAT16_DEBUG > 1
+	printstring "ClusterID",0
+.endif
 ;   Offset to Startcluster + 2
 	ldd	temp,z+0x1A
 	st	y+,temp
+.if FAT16_DEBUG > 1
+	rcall	printhex
+.endif
 	ldd	temp,z+0x1B
 	st	y+,temp	
+.if FAT16_DEBUG > 1
+	rcall	printhex
+.endif
 	ldi	temp,0
 	st	y+,temp
-	st	y+,temp
+	st	y+,temp
 
-;   Filesize in Bytes - 2,4,8,16,32,64,128,256,512 
+.if FAT16_DEBUG > 1
+	printnewline
+.endif
+
+;   Filesize in Bytes
 ;	ldd	temp,z+0x1C
 ;	st	y+,temp
 ;	ldd	temp,z+0x1D
@@ -559,60 +707,62 @@ fat_look_store:
 	mov	zh,_0
 
 	lsr	zh
-	ror zl
-	ror xh
-	ror xl
+	ror 	zl
+	ror 	xh
+	ror 	xl
 
 ;   store ammount of sectors in partitiontable	
-	st  y+,xl
-	st  y+,xh
-	st  y+,zl
-	st  y+,zh
-
+	st	y+,xl
+	st	y+,xh
+	st	y+,zl
+	st	y+,zh
+
+.if FAT16_DEBUG > 1
+; Test finding of the first sector
+	
+	ldd	xl,z+0x1A
+	ldd	xh,z+0x1B
+
+	rcall	fat_gethostsec
+
+	printstring "Begin of Image at: ",0
+	mov	temp ,yl
+	mov	temp2,yh
+	rcall	printhexw
+	mov	temp ,xl
+	mov	temp2,xh
+	rcall	printhexw
+	printnewline
+
+.endif
 ; Check for another free entry in partition table
 	lds	temp,ndisks
 	inc	temp
 	sts	ndisks,temp
 	
+	cpi	temp,MAXDISKS
+	breq	fat_scan_end	
 
-; Test finding of the first sector
-	ldd	xl,z+0x1A
-	ldd	xh,z+0x1B
-	ldi	zl,0
-
-	rcall	fat_gethostsec
+	jmp	fat_scan_for_more	
 
-.if FAT16_DEBUG > 1
-	printstring "Begin of Image at: ",0
-	mov		temp ,yl
-	mov		temp2,yh
-	rcall printhexw
-	mov		temp ,xl
-	mov		temp2,xh
-	rcall printhexw
-	printnewline
-
-.endif
-	
-;	cp		temp,MAXDISKS
-;	brne	fat_scan_for_more	
+fat_scan_end:
 		
 	ret
 
 
-; ====================================================================
+; ============================================================================
 ; Function: Cluster to HostSector 
-; ====================================================================
-; Parameters: [in]	xh,xl			Cluster Number
-;			  [out]	yh,yl,xh,xl		Sector Number on Disk
-; --------------------------------------------------------------------
+; ============================================================================
+; Parameters:	[in]	xh,xl		Cluster Number
+;		[out]	yh,yl,xh,xl	Sector Number on Disk
+; ----------------------------------------------------------------------------
 ; Registers  : 	
 ; Variables  : 	[used]	fat_clustersize	Ammount of Sectors per Cluster
-;				[changes] temp
-; --------------------------------------------------------------------
+;		[changes] temp
+; ----------------------------------------------------------------------------
 ; Description:
 ; ! Only works with Clustersizes 2,4,8,16,32,64,128 !
-; ====================================================================
+; ============================================================================
 fat_gethostsec:
 
 ;	Get Offset into Data area of Disk
@@ -620,49 +770,50 @@ fat_gethostsec:
 
 
 ;	add begin of data area to offset
-	lds		temp,fat_ptr2dat+0
-	add		xl,temp
-	lds		temp,fat_ptr2dat+1
-	adc		xh,temp
-	lds		temp,fat_ptr2dat+2
-	adc		yl,temp
-	lds		temp,fat_ptr2dat+3
-	adc		yh,temp
+	lds	temp,fat_ptr2dat+0
+	add	xl,temp
+	lds	temp,fat_ptr2dat+1
+	adc	xh,temp
+	lds	temp,fat_ptr2dat+2
+	adc	yl,temp
+	lds	temp,fat_ptr2dat+3
+	adc	yh,temp
 	ret
 
-; ====================================================================
+; ============================================================================
 ; Function: Cluster to Sector 
-; ====================================================================
-; Parameters: [in]	xl,xh			Cluster Number
-;			  [out]	xl,xh,yl,yh		Sector Number
-; --------------------------------------------------------------------
-; Registers  : 	
-; Variables  : 	[used]	fat_clustersize	Ammount of Sectors per Cluster
-;				[changes] temp
-; --------------------------------------------------------------------
-; Description:
-; ! Only works with Clustersizes 2,4,8,16,32,64,128 !
-; ====================================================================
+; ============================================================================
+; Registers:	[in]	xl,xh			Cluster Number
+;	 	[out]	xl,xh,yl,yh		Sector Number
+; Variables:	[in]	fat_clustersize		Ammount of Sectors per Cluster
+;		[out]	temp			=0
+; ----------------------------------------------------------------------------
+; Description:
+; Calculates the logical Sectornumber given the physical ClusterNumber
+; and the size of a Cluster un sectors.
+;
+; ! Only works with Clustersizes 2,4,8,16,32,64,128,512,1024 !
+; ============================================================================
 fat_clusttosec:
 	clr 	yl
-	clr		yh
+	clr	yh
 
-	ldi		temp,2
-	sub		xl,temp		; Substract the 2 reserved clusters
-	sbc		xh,_0
+	ldi	temp,2
+	sub	xl,temp		; Substract the 2 reserved clusters
+	sbc	xh,_0
 
-	lds		temp,fat_clustersize
-	lsr		temp
+	lds	temp,fat_clustersize
+	lsr	temp
 
 fat_c2s_loop:
-	tst		temp
+	tst	temp
 	breq	fat_c2s_end
-	lsr		temp
+	lsr	temp
 
-	lsl		xl
-	rol		xh
-	rol		yl
-	rol		yh
+	lsl	xl
+	rol	xh
+	rol	yl
+	rol	yh
 	rjmp	fat_c2s_loop
 
 fat_c2s_end:
@@ -671,42 +822,41 @@ fat_c2s_end:
 ; ====================================================================
 ; Function: Searches a physical Cluster, given the logical Cluster
 ; ====================================================================
-; Parameters
-; --------------------------------------------------------------------
-; Registers  : [r] xh,xl		logical- Cluster 
-;			   [w] yh,yl		physical- Cluster
+; Registers:	[in]	xh,xl	logical- Cluster 
+;		[out]	yh,yl	physical- Cluster
+; Variables:
 ; --------------------------------------------------------------------
 ; Description:
 ; ====================================================================
 fat_find_phsy_clust:
 	mov     temp2,xl
-	lds		xl,hostdsk
+	lds	xl,hostdsk
 
 	rcall 	dsk_getpartentry	; get partition entry
 	mov 	xl,temp2
 
 ;	Get First FAT- Cluster Number of Diskimage
 	
-	ldd		yl,z+1
-	ldd		yh,z+2
+	ldd	yl,z+1
+	ldd	yh,z+2
 
 .if FAT16_DBG_FAT > 0
 	printstring "Search log. Cluster ",0
-	mov temp,xl
-	mov temp2,xh
-	rcall printhexw
+	mov	temp,xl
+	mov	temp2,xh
+	rcall	printhexw
 	printnewline
 		
 	printstring "Search phys. Cluster ",0
-	mov temp ,yl
-	mov temp2,yh
-	rcall printhexw
+	mov	temp ,yl
+	mov	temp2,yh
+	rcall	printhexw
 	printnewline
 .endif
 
 fat_next_phsy_clust:	
-	cp		xl,_0
-	cpc		xh,_0
+	cp	xl,_0
+	cpc	xh,_0
 	breq	fat_found_phsy_clust
 ;	Get Next Cluster from Fat
 
@@ -717,89 +867,106 @@ fat_next_phsy_clust:
 ; 	in	zh,zl:		Pointer to Word within the Sector to read	
 ;   in	yh..xl:	Start sector number (LBA)
 ;	out	zh,zl	: word thats been read
-	push xl
-	push xh
+	push 	xl
+	push 	xh
 
 ;   Create FAT Offset Value
 	clr	zh
-	mov zl,yl
+	mov 	zl,yl
 	lsl	zl
-	rol zh
+	rol 	zh
 ;   Get FAT Start
-	mov temp,yh
-	lds xl,fat_ptr2fat
-	lds xh,fat_ptr2fat+1
-	lds yl,fat_ptr2fat+2
-	lds yh,fat_ptr2fat+3
+	mov 	temp,yh
+	lds 	xl,fat_ptr2fat
+	lds 	xh,fat_ptr2fat+1
+	lds 	yl,fat_ptr2fat+2
+	lds 	yh,fat_ptr2fat+3
 ;   Add Cluster offset within sector
 	add	xl,temp
 	adc	xh,_0
-	adc yl,_0
-	adc yh,_0
-	call mmcReadWord
+	adc 	yl,_0
+	adc 	yh,_0
+	call 	mmcReadWord
 
-	pop xh
-	pop xl
+	pop 	xh
+	pop 	xl
 
-	mov yl,zl
-	mov yh,zh
+	mov 	yl,zl
+	mov 	yh,zh
 
 ;	Check next logical Cluster
-	ldi		zl,1
-	sub		xl,zl
-	sbc		xh,_0
+	ldi	zl,1
+	sub	xl,zl
+	sbc	xh,_0
 	rjmp	fat_next_phsy_clust
 	
 ; Found the physical cluster
 fat_found_phsy_clust:	
 .if FAT16_DBG_FAT > 0
 	printstring "Found phys. Cluster at:",0
-	mov temp,yl
-	mov temp2,yh
-	rcall printhexw
+	mov 	temp,yl
+	mov 	temp2,yh
+	rcall	printhexw
 	printnewline
 .endif	
 
 	ret
 
-; ====================================================================
-; Function: Does a Disk write operation
-; ====================================================================
-; Parameters
-; --------------------------------------------------------------------
-; Registers  : none
-; Variables  : [r] seekdsk		Number of Disk to Read
-;			   [r] seeksec		Sector to read
-;              [r] seektrk		Track  to read
-; hostdsk = host disk #,  (partition #)
-; hostlba = host block #, relative to partition start 
-; Read/Write "hostsize" bytes to/from hostbuf
-; --------------------------------------------------------------------
+; ============================================================================
+; Function: This Routine searches for the Sector within an Imagefile 
+; ============================================================================
+; Registers:	[out] xl,xh,yl,yh	Pointer to the Sector on the SD-Card
+;		[out] temp		Error- Variable (0= No Error)
+; Variables:	[in] hostdsk		host disk #,  (partition #)
+; 		[in] hostlba		host block #, relative to part.start
+;		[in] fat_last_dsk	number of disk with entry in cache
+;		[in] fat_log_clust	last searched logical cluster
+;		[in] fat_clust_offset	offset within the cluster
+;               [in] fat_clust_ptr	sector of last real cluster
+; ----------------------------------------------------------------------------
 ; Description:
-; ====================================================================
+; This Routine uses the variables hostdsk and hostlba to find an Sector
+; in the Imagefile.
+; The CP/M Sector given within "hostlba" are splited to a logical Cluster-
+; Number and the Subsector within this logical Cluster.
+; logical Cluster Number = hostlba / fat_clustersize
+; The logical Cluster Number will be compared to the logical Cluster- Number
+; within the Cache. When this Clusters are the same and the DiskID's are
+; also the same, then the cached physical Sector will be used.
+; When the Clusters or the Disks don't match, a seek for the physical
+; Cluster is performed. This seek is done thru an access over the FAT of
+; the FAT16 Partition. The Routine starts at the first Cluster of the 
+; Imagefile and goes along the linked list of Clusternumber till it reaches
+; the searched cluster. The found Clusternumber will be used to calculate
+; the Sektor where this Cluster lies on the SD- Card. Both the found physical
+; Cluster and the logical Cluster together with the physical Sectornumber
+; are stored in the cache.
+; The last step done is to add the SubSectorOffset to the found physical
+; Sector. This gives the pointer to the Sector to be read and or written.
+; ============================================================================
 
 fat_hostparam:
-	lds		xl,hostdsk
+	lds	xl,hostdsk
 
 
-	rcall dsk_getpartentry	; get partition entry
+	rcall	dsk_getpartentry	; get partition entry
 
 fat_hostlend:
-	lds		temp ,hostlba
-	lds		temp2,hostlba+1
-	lds		temp3,hostlba+2
+	lds	temp ,hostlba
+	lds	temp2,hostlba+1
+	lds	temp3,hostlba+2
 
 
-	ldd		xl,z+5			; get size of disk in sectors
-	ldd		xh,z+6
-	ldd		yl,z+7
+	ldd	xl,z+5			; get size of disk in sectors
+	ldd	xh,z+6
+	ldd	yl,z+7
 	
-	cp		temp,xl			; check given sector against disksize
-	cpc		temp2,xh
-	cpc		temp3,yl
+	cp	temp,xl			; check given sector against disksize
+	cpc	temp2,xh
+	cpc	temp3,yl
 	brcs	fat_hp1
 	
-	clr		temp
+	clr	temp
 	ret
 
 fat_hp1:
@@ -811,131 +978,130 @@ fat_hp1:
 	mov 	yl,temp3
 	mov 	yh,_0
 ; Divide logical Sectornumber by size of Cluster in sectors
-	lds		zl,	fat_clustersize
+	lds	zl,fat_clustersize
 	lsr     zl
 fat_search_clst_lp:
-	tst		zl
+	tst	zl
 	breq	fat_found_clst
 
-	lsr		yh
-	ror		yl
-	ror		xh
-	ror		xl
+	lsr	yh
+	ror	yl
+	ror	xh
+	ror	xl
 	
-	lsr		zl
+	lsr	zl
 
 	rjmp	fat_search_clst_lp	
 fat_found_clst:			
 ; at this point xh and xl are carying the logical cluster number
 ;	printstring "find subsector"
 ; ################# Get Subsector within the logical Cluster for later use
-	mov		yl,xl
-	lds		zl,	fat_clustersize
-	lsr		zl
+	mov	yl,xl
+	lds	zl,fat_clustersize
+	lsr	zl
 fat_search_clst_lp2:
-	tst		zl
+	tst	zl
 	breq	fat_found_subsec
-	lsl		yl
+	lsl	yl
 
-	lsr		zl
+	lsr	zl
 	rjmp	fat_search_clst_lp2		
 
 fat_found_subsec:
-	mov		zl,temp
-	sub		zl,yl
-	sts		fat_clust_offset,zl
+	mov	zl,temp
+	sub	zl,yl
+	sts	fat_clust_offset,zl
 
 ; Check against last HOSTDISK searched
-	lds		yl,fat_last_dsk
-	lds		yh,hostdsk
-	cp		yl,yh
+	lds	yl,fat_last_dsk
+	lds	yh,hostdsk
+	cp	yl,yh
 	brne	fat_wrong_cache_clst
 
 ; Check against last Cluster searched
-	lds		yl,fat_log_clust
-	lds		yh,fat_log_clust+1
+	lds	yl,fat_log_clust
+	lds	yh,fat_log_clust+1
 
-	cp		yl,xl
+	cp	yl,xl
 	brne	fat_wrong_cache_clst
-	cp		yh,xh
+	cp	yh,xh
 	brne	fat_wrong_cache_clst
 
 ;   Last Cluster = searched Cluster -> get Sectornumber from cache
-	lds		xl,fat_clust_ptr
-	lds		xh,fat_clust_ptr+1
-	lds		yl,fat_clust_ptr+2
-	lds		yh,fat_clust_ptr+3
+	lds	xl,fat_clust_ptr
+	lds	xh,fat_clust_ptr+1
+	lds	yl,fat_clust_ptr+2
+	lds	yh,fat_clust_ptr+3
 
 	rjmp	fat_add_offset
 
-; ################# Cluster is not in cache, so we must search for it
+;  Cluster is not in cache, so we must search for it
 fat_wrong_cache_clst:
-	lds		yl,hostdsk
-	sts		fat_last_dsk,yl
-	sts		fat_log_clust,xl
-	sts		fat_log_clust+1,xh
+	lds	yl,hostdsk
+	sts	fat_last_dsk,yl
+	sts	fat_log_clust,xl
+	sts	fat_log_clust+1,xh
 
-; ################# Map Logical Cluster-Number to "Physical" Cluster Number using the FAT
+;  Map Logical Cluster-Number to "Physical" Cluster Number using the FAT
 	rcall   fat_find_phsy_clust
 
-; ################# Get StartSector of "physical" Cluster
+;  Get StartSector of "physical" Cluster
 	mov 	xl,yl
-	mov		xh,yh
+	mov	xh,yh
 	rcall   fat_gethostsec
 ; Found the physical sector
 .if FAT16_DBG_FAT > 0
 	printstring "Found phys. Sector at:",0
-	mov temp,yl
-	mov temp2,yh
-	rcall printhexw
-	mov temp,xl
-	mov temp2,xh
-	rcall printhexw
+	mov	temp,yl
+	mov	temp2,yh
+	rcall	printhexw
+	mov	temp,xl
+	mov	temp2,xh
+	rcall	printhexw
 	printnewline
 .endif	
 
 ;   Save the found Sector for later use into cache
-	sts		fat_clust_ptr  ,xl
-	sts		fat_clust_ptr+1,xh
-	sts		fat_clust_ptr+2,yl
-	sts		fat_clust_ptr+3,yh
+	sts	fat_clust_ptr  ,xl
+	sts	fat_clust_ptr+1,xh
+	sts	fat_clust_ptr+2,yl
+	sts	fat_clust_ptr+3,yh
 
 ;   Add- Subsector to Startsector 
 fat_add_offset:
-	lds		zl,fat_clust_offset
-	add		xl,zl
-	adc		xh,_0
-	adc		yl,_0
-	adc		yh,_0
+	lds	zl,fat_clust_offset
+	add	xl,zl
+	adc	xh,_0
+	adc	yl,_0
+	adc	yh,_0
 
 ; Found the physical sector
 .if FAT16_DBG_FAT > 0
 	printstring "Sector with Offset at:",0
-	mov temp,yl
-	mov temp2,yh
-	rcall printhexw
-	mov temp,xl
-	mov temp2,xh
-	rcall printhexw
+	mov	temp,yl
+	mov	temp2,yh
+	rcall	printhexw
+	mov	temp,xl
+	mov	temp2,xh
+	rcall	printhexw
 	printnewline
 .endif
 
-	ori		temp,255
+	ori	temp,255
 fat_hpex:
 	ret
 
-; ====================================================================
+; ============================================================================
 ; Function: Does a Disk write operation
-; ====================================================================
-; Parameters
-; --------------------------------------------------------------------
-; Registers  : none
-; Variables  : [r] seekdsk		Number of Disk to Read
-;			   [r] seeksec		Sector to read
-;              [r] seektrk		Track  to read
-; --------------------------------------------------------------------
-; Description:
-; ====================================================================
+; ============================================================================
+; Registers: 	[out]	temp	Error-Variable ( 0= No Error)		
+; Variables:	[in]	hostdsk	host disk #,  (partition #)
+; 		[in]	hostlba	host block #, relative to part.start
+;		[in]	hostbuf Sector to be written
+; ----------------------------------------------------------------------------
+; Description:
+; This Routine writes a Sector to the Imagefile inside an FAT16 Partition.
+; ============================================================================
 
 fat_writehost:
 .if FAT16_RWDEBUG > 1
@@ -946,39 +1112,39 @@ fat_writehost:
 	breq	fat_rdwr_err
 	
 	;call	mmcWriteSect	; disabled till read is functioning
-	tst		temp
+	tst	temp
 	breq	fat_rdwr_ok
 	
 	rcall	mgr_init_partitions
-	cbr		temp,0x80
+	cbr	temp,0x80
 	breq	fat_rdwr_err
 
 	rcall	fat_hostparam
 	breq	fat_rdwr_err
 	;call	mmcWriteSect	; disabled till read is functioning
-	tst		temp
+	tst	temp
 	brne	fat_rdwr_err
 	rjmp	fat_rdwr_ok
 
 fat_rdwr_ok:
-	sts		erflag,_0
+	sts	erflag,_0
 	ret
 
 fat_rdwr_err:
-	sts		erflag,_255
-	ret
-; ====================================================================
+	sts	erflag,_255
+	ret
+
+; ============================================================================
 ; Function: Does a Disk read operation
-; ====================================================================
-; Parameters
-; --------------------------------------------------------------------
-; Registers  : none
-; Variables  : [r] seekdsk		Number of Disk to Read
-;			   [r] seeksec		Sector to read
-;              [r] seektrk		Track  to read
-; --------------------------------------------------------------------
-; Description:
-; ====================================================================
+; ============================================================================
+; Registers: 	none
+; Variables:	[in]	hostdsk		host disk #,  (partition #)
+; 		[in]	hostlba		host block #, relative to part.start
+;		[out]	hostbuf 	Sector read by this routine
+; ----------------------------------------------------------------------------
+; Description:
+; This Routine reads a Sector from the Imagefile inside an FAT16 Partition. 
+; ============================================================================
 
 fat_readhost:
 .if FAT16_RWDEBUG > 1
@@ -999,25 +1165,25 @@ fat_readhost:
 	movw	temp,x
 	movw	temp3,y
 	rcall	print_ultoa
-	pop		temp
-	pop		temp2
-	pop		temp3
-	pop		temp4
+	pop	temp
+	pop	temp2
+	pop	temp3
+	pop	temp4
 	printnewline
 .endif
 	
 	call	mmcReadSect
-	tst		temp
+	tst	temp
 	breq	fat_rdwr_ok
 
 	rcall	mgr_init_partitions
-	cbr		temp,0x80
+	cbr	temp,0x80
 	breq	fat_rdwr_err
 
 	rcall	fat_hostparam
 	breq	fat_rdwr_err
 	call	mmcReadSect
-	tst		temp
+	tst	temp
 	brne	fat_rdwr_err
 
 #endif