SCL format

SCL Disk Image Format

The SCL format is a compact representation of a TRD disk image. It stores only the file headers and the used sectors.

An emulator should build a real disk image on the fly from SCL data to use it for disk emulation.

SCL file structure

The file begins with a 8 byte 'magic': SINCLAIR, then the number of files, the file headers an after that all the data blocks.

Offset	Length	Comment
0x0000	9	SCL file header
0x0009	N x 14	File headers
0x0009 + N x 14	DATA LENGTH	Sector data

SCL file header

Offset	Length	Comment
0x0000	8	Signature "SINCLAIR"
0x0008	1	Number of files (N)

File headers

Offset	Length	Comment
0x0000	14	1st file header entry
0x000e	14	2nd file header entry
...	...	...
0x0000 + (N-1) x 14	14	Nth file header entry

File header entry

The file headers structure is the same as on the disk, except the last two bytes (start sector, start track).

Offset	Length	Comment
0x0000	8	File name
0x0008	1	File type
0x0009	3	File parameters (based on type)
0x000d	1	File length in sectors

Files data

Offset	Length	Comment
0x0000	1st file length x 256	1st file data
0x0000 + 1st file length x 256	2nd file length x 256	2nd file header entry
...	...	...
0x0000 + ....	last file length	Nth file header entry