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The SDSC tag was introduced in 2001 to provide a standard way to tag homebrew software.
The SDSC tag is found at offset $7fe0, directly before the standard ROM header (if it's in the usual place).
The first four bytes are the ASCII text "SDSC
". This is used to show that the header is present.
The version of the program, with the first byte being the major version and the second byte the minor version. Each is in BCD, thus ranging from 0-99. For example, version 0.01 is stored as 00 01
, version 10.46 is stored as 10 46
.
The date of release (or compilation) is stored in the order day (1 byte BCD), month (1 byte BCD), year (2 bytes little-endian BCD). For example, 27th March 2011 is stored as 27 03 11 20
; today's date (February 22, 2019) is stored as 22 02 19 20
.
The (little-endian) ROM address of a zero-terminated ASCII string containing the author's name. The string should contain only printable characters in the range 0-127. Values $ffff and $0000 indicate no author name.
The (little-endian) ROM address of a zero-terminated ASCII string containing the name of the program. The string should contain only printable characters in the range 0-127. Value $ffff indicates no program name.
The (little-endian) ROM address of a zero-terminated ASCII string containing a description of the program. The string should contain only printable characters in the range 0-127, and line breaks. Line breaks can be any of CR, CRLF and LF. Value $ffff indicates no description.