Docs » Autodocs » trackdisk.device » CMD_UPDATE
CMD_UPDATE/ETD_UPDATE -- write out the track buffer if it is dirty.
The trackdisk device does not write data sectors unless it isCMD_WRITE()
necessary (you request that a different track be used) or until the
user requests that an update be performed. This improves system speed
by caching disk operations. These commands ensure that any
buffered data is flushed out to the disk. If the track buffer has not
been changed since the track was read in, these commands do nothing.
ETD_UPDATE command checks for diskchange.
IO REQUEST INPUT
io_Device preset by the call to OpenDevice()
io_Unit preset by the call to OpenDevice()
io_Command CMD_UPDATE or ETD_UPDATE
io_Flags 0 or IOF_QUICK
iotd_Count (ETD_UPDATE only) maximum allowable change counter
IO REQUEST RESULT
io_Error - 0 for success, or an error code as defined in