Color Computer CoCo SDC, Manual

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COCO SDC | 27
Byte Offset Length Description
0 2 ASCII ‘d’ and ‘k’.
2 2 Header size (little-endian).
4 1 Version of VDK format.
5 1 Backwards compatibility version.
6 1 Identity of file source.
7 1 Version of file source.
8 1 Number of tracks.
9 1 Number of sides.
10 1 Flags:
Bit Meaning Bit Meaning
0 Write Protect 1 Advisory lock
2 Mandatory Lock 3 Disk Set
4 Unused 5 Unused
6 Unused 7 Unused
11 1 Compression flags and name length.
The CoCo SDC will honor a Number Of Sides value of 1 or 2. It will also honor the Write Protect
bit.
SDF Images
The SDF image format is used to represent floppy disks that have a non-standard layout which is
anything other than 18 sectors per track and 256 bytes per sector using standard numbering of
the tracks and sectors. The SDF format is similar to the DMK format supported by most CoCo
emulators. It has been augmented to provide better performance within the limited resources of
the Atmega328 micro controller.
The dmk2sdf program has been created for converting a DMK image to the SDF format. A Win32
command line executable along with the ANSI C source code can be downloaded using the link:
https://goo.gl/q61D6s.