RE: Disk-images

From: COPLIN, Nicholas. (ncoplin_at_orbeng.com.au)
Date: 2000-08-01 08:00:48

Hello Ruud,

The file formats.zip distributed with 64COPY has a good listing of the D64,
D71 and D81 formats as well as many other C64 formats. BAM formats are
available in the etext files under Project64.

As far as my experiences go, GEOS "cracked" disks copy as D64 format without
the need for error info, so GEOS itself doesn't rely on trickery after the
booting operation. I've never tested my original disks as I do my D64 filing
with Trans64 which doesn't write back error info to real 1541 disks...

Teledisk can also back up the FD2000 disks, but it uses a compressed format
for the PC image file. The D2M format that Womo uses is in simple
block/track/sector format, but the rules get tricky when native and emulated
partitions are mixed on the one disk....

- Nick



> -----Original Message-----
> From:	g.j.p.a.a.baltissen@kader.hobby.nl
> [SMTP:g.j.p.a.a.baltissen@kader.hobby.nl]
> Sent:	None
> To:	cbm-hackers@dot.tcm.hut.fi
> Subject:	Disk-images
> 
> Hallo allemaal,
> 
> D64 is generally accepted is THE disk-image for 1541-floppies and its
> IEEE-
> equivalents. There have been discussions about other formats but I haven't
> seen specific specs yet. So intend to make a page containing these specs.
> You will notice that the directory/BAM-specs for D71 and D81 are missing.
> I
> have those of D71 somewhere in a book but haven't found that book yet :(
> So
> if someone has them at hand, feel free to mail them please.
> 
> The D81-specs are missing too but for the simple reason I have no idea at
> all how they look neither do I have any docs. I also want to know what the
> filecode for a sudirectory is on a 1581, please.
> 
> The "images / drives" list is probably not complete. Feel free to add
> other
> drives.
> 
> No further specs for D16 are given for the simple reason that I am still
> working out some minor details. (like subdirectories)
> 
> Three more questions:
> - Star Commander adds in case of an error an error-log to the D64-file. Is
> this 
> part of the D64-standard and if yes, how does it look like?
> - GEOS-files have there own codes. Does anybody know which ones exists?
> - I have the idea that GEOS saves it files in an other way then using the 
> normal 1541-DOS. If it is different, who could explain this please?
> 
> ==========================================================================
> =
> 
> The known images until so far.
> 
> Theoretically there exists a image-type for every format once used by the
> Commodore-drives but some probably won't be used used for very simple
> reason that the drives are very rare.
> 
> 
> The following images can be used for the listed drives:
> 
> D40 - 2040, 3040
> D60 - 9060
> D64 - 2031, 4040, 1540, 1541, 1551, 1570
> D71 - 1571
> D80 - 8050
> D81 - 1581
> D82 - 8250, SDF1001
> D90 - 9090
> 
> 
> Additional I created the D16-image. This image handles an imaginary 1541-
> drive capable of handling 255 tracks with 256 sectors each. This is about
> 16 MB, therefor the "16" in the "D16". I intend to use it in several of my
> own programs.
> 
> 
> At this moment only one image-type is generally accepted: D64. Two other,
> D80 and D82 are used by VICE. Creating a Dxx-file on a PC is no problem:
> there exist several programs which enable you to connect an IEC- or IEEE-
> drive directly to your PC and to read all the sectors one by one. The
> problem lays in handling the file by the PC. To be able to handle a Dxx-
> file you need to know four things:
> 
> - How many tracks has the original disk
> - How many sectors does each track contain
> - The structure of the BAM
> - The structure of the directory
> 
> 
> Tracks and sectors    
> 
> Image Tracks      Sectors
> 
> D16   1 - 255        256
> 
> 
> D40   1 - 17         21
>       18 - 24        20
>       25 - 30        18
>       31 - 35        17
> 
> 
> D60   1 - 612        32
> 
> 
> D64   1 - 17         21
>       18 - 24        19
>       25 - 30        18
>       31 - 35        17
> 
> 
> D71   1 - 17         21
>       18 - 24        19
>       25 - 30        18
>       31 - 35        17
>       36 - 52        21
>       53 - 59        19
>       60 - 65        18
>       66 - 70        17
> 
> 
> D80   1 - 39         29
>       40 - 53        27
>       54 - 64        25
>       65 - 77        23
> 
> 
> D82   1 - 39         29
>       40 - 53        27
>       54 - 64        25
>       65 - 77        23
>       76 - 116       29
>       117 - 130      27
>       131 - 141      25
>       142 - 154      23
> 
> D90   1 - 918        32
> 
> 
> 
> The Directory header block / BAM   
> 
> Image Byte  Contents    Definition
> 
> D40 - Directory-header + BAM at 18/0
>         0      18       Track of first directory block
>         1       1       Sector of first directory block
>         2       1       Indicates version 1 format
>         3       0       Future use
>         4-143           Bitmap of available blocks
>       144-161           Diskname padded with shifted space
>       162-163           Disk ID
>       164-170  160      Shifted space
>       171-255    0      Not used
> 
> D64 - Directory-header + BAM at 18/0
>         0      18       Track of first directory block
>         1       1       Sector of first directory block
>         2      65       Indicates version 4040 format
>         3       0       Future use
>         4-143           Bitmap of available blocks
>       144-161           Diskname padded with shifted space
>       162-163           Disk ID
>       164     160       Shifted space
>       165      50       \
>       166      65       -=> 2A, indicates DOS-version and format type
>       167-170 160       Shifted space
>       171-255   0       Not used
> 
> 
> D80 - Directory-header at 39/0
>         0      38       Track of first BAM block
>         1       0       Sector of first directory block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4-  5   0       Unused
>         6- 21           Diskname padded with shifted space
>        22- 23 160       Shifted space
>        23- 25           Disk ID
>        26     160       Shifted space
>        27      50       \
>        28      67       -=> 2C, indicates DOS-version and format type
>        29- 32 160       Shifted space
>        33-255   0       Not used
> 
>       BAM table at 38/0
>         0      38       Track of second BAM block
>         1       3       Sector of second BAM block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4       1       Lowest tracknumber in this BAM block
>         5      51       Highest tracknumber+1 in this BAM block
>         6               Number of unused blocks on track 1
>         7- 10           Bitmap of available blocks on track 1
>        11-255           BAM for tracks 2-50, 5 bytes per track
> 
>       BAM table at 38/3
>         0      39       Track of first directory block
>         1       1       Sector of first directory block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4      51       Lowest tracknumber in this BAM block
>         5      78       Highest tracknumber+1 in this BAM block
>         6               Number of unused blocks on track 51
>         7- 10           Bitmap of available blocks on track 51
>        11-140           BAM for tracks 51-77, 5 bytes per track
>       141-255           Unused
> 
> 
> D82 - Directory-header at 39/0
>         0      38       Track of first BAM block
>         1       0       Sector of first BAM block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4-  5   0       Unused
>         6- 21           Diskname padded with shifted space
>        22- 23 160       Shifted space
>        23- 25           Disk ID
>        26     160       Shifted space
>        27      50       \
>        28      67       -=> 2C, indicates DOS-version and format type
>        29- 32 160       Shifted space
>        33-255   0       Not used
> 
>       BAM table at 38/0
>         0      38       Track of second BAM block
>         1       3       Sector of second BAM block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4       1       Lowest tracknumber in this BAM block
>         5      51       Highest tracknumber+1 in this BAM block
>         6               Number of unused blocks on track 1
>         7- 10           Bitmap of available blocks on track 1
>        11-255           BAM for tracks 2-50, 5 bytes per track
> 
>       BAM table at 38/3
>         0      38       Track of third BAM block
>         1       6       Sector of third BAM block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4      51       Lowest tracknumber in this BAM block
>         5     101       Highest tracknumber+1 in this BAM block
>         6               Number of unused blocks on track 51
>         7- 10           Bitmap of available blocks on track 51
>        11-255           BAM for tracks 52-100, 5 bytes per track
> 
>       BAM table at 38/6
>         0      38       Track of fourth BAM block
>         1       9       Sector of fourth BAM block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4     101       Lowest tracknumber in this BAM block
>         5     151       Highest tracknumber+1 in this BAM block
>         6               Number of unused blocks on track 101
>         7- 10           Bitmap of available blocks on track 101
>        11-255           BAM for tracks 102-150, 5 bytes per track
> 
>       BAM table at 38/9
>         0      39       Track of first directory block
>         1       1       Sector of first directory block
>         2      67       Indicates version 8050 format
>         3       0       Future use
>         4     151       Lowest tracknumber in this BAM block
>         5     155       Highest tracknumber+1 in this BAM block
>         6               Number of unused blocks on track 151
>         7- 10           Bitmap of available blocks on track 151
>        11- 25           BAM for tracks 152-154, 5 bytes per track
>        26-255           Unused
> 
> ==========================================================================
> =
> Groetjes, Ruud
> 
> 
> -
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