gtpd1m0gDatabase Reference

Extended MCHR File Address

DASDs that are supported by the TPF system require a 7-byte hardware address to physically access a record, plus a 2-byte symbolic module number. This is the address that must be used by channel programs, including those generated for the file data chain macro (FDCTC) and the extended form of the FNSPC and FLSPC macros under the TPF system. Figure 5 shows the formats of extended MCHR file addresses used to store and retrieve TPF records.