| 16–31 || Block IDs where to find the file data || 1 byte is used per 1KB block.
|}
Note: AMSDOS files are usually stored with an [[AMSDOS Header]] but can also be headerless. CP/M files do not have headers.
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'''Sector''': The smallest physically addressable unit on a disk, 512 bytes in size on Amstrad CPC. CP/M accessed the disk at the sector level, though users typically worked with records.
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==== File Headers ====
Cassette files are subdivided into 2K blocks, each of which is preceded by a 64-byte header.
AMSDOS files are usually stored with a 128-byte [[AMSDOS Header]] but can also be headerless, depending on the contents of the file. Unprotected ASCII files do no have header.
CP/M files do not have headers.
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