
DISK DRIVE OPERATION
6.4.21 Set Multiple Mode (C6h)
This command enables the drive to perform Read and Write Multiple operations and establishes the block count for these commands. Refer to section 6.6.3 for the protocol.
The Sector Count register is loaded with the number of sectors per block. Drives support block sizes of 2, 4, 8, and 16 sectors. Upon receipt of the command, the drive sets BSY=1 and checks the Sector Count register.
If the Sector Count register contains a valid value and the block count is supported, the value is loaded for all subsequent Read Multiple and Write Multiple commands and execution of those commands is enabled. If a block count is not supported, an Aborted Command error is posted, and Read Multiple and Write Multiple commands are disabled.
If the Sector Count register contains 0 when the command is issued, Read and Write Multiple commands are disabled. At
6.4.22 Sleep (99h, E6h)
This command is the only way to cause the drive to enter Sleep Mode. The drive is spun down, and when it is stopped, BSY is cleared, an interrupt is generated, and the interface becomes inactive.
The only way to recover from Sleep mode without a reset or
A drive shall not
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