9.0 CDM Message I/O Functions

For convenience, the following table lists the CDM I/O functions in alphabetical order. However, in the remainder of this document, they are presented in numerical order.

I/O Function	Code
Locate Data Blocks (0x002B)	0x002B
Multiple File Mark (0x0027)	0x0027
Multiple Set Mark (0x0029)	0x0029
Position Media (0x002D)	0x002D
Random Read (0x0020)	0x0020
Random Write (0x0021)	0x0021
Random Write Once (0x0022)	0x0022
Reset Queue (0x0025)	0x0025
Select Partition (0x002C)	0x002C
Sequential Read (0x0023)	0x0023
Sequential Write (0x0024)	0x0024
Single File Mark (0x0026)	0x0026
Single Set Mark (0x0028)	0x0028
Space Data Blocks (0x002A)	0x002A

CDMs are provided with the following:

A comprehensive reference for the I/O function operations [packaged in the CDMMessageStruct] that a CDM can expect to receive.
A reference outlining how a CDM should interpret the contents of each data field in the CDMMessageStruct so that it can properly build a corresponding HACB request.
A list of valid Media Manager completion codes used in completing a CDM message at the end of its request cycle. These completion codes are passed to the Media Manager through CDI_Complete_Message