Sequential Read (0x0023)
Reads sequential data from tape.
Parameters
- function
- 0x0023 – sequential read request.
- parameter0
- Specifies the number of units to be read, where
units refers to what was formerly called sectors on fixed media.
- parameter1
- Not used.
- parameter2
- Not used.
- bufferLength
- The size of the buffer (that is, the number of units
multiplied by the unit size) in bytes. The number of units (parameter0)
cannot exceed the maximum number of units as prescribed in the blockSize to
the UpdateInfoStruct structure
used when the CDM bound to the target device. Additionally, the
device's unit size (unitSize field) is specified
in this structure.
- buffer
- Points to a buffer in memory where the data is to
be read.
- returnParameter
- The number of units read.
The returnParameter is not a data member
of the CDM message structure [see CDMMessageStruct]. However, CDMs supporting
this function are required to provide the data specified by returnParameter.
The Media Manager passes this value on to the application, and the
CDM passes this value to the Media Manager as an input parameter to CDI_Complete_Message.