Specifications

Data Structures

1.19 Unit Control Block (UCB)

In this case, too, the driver must ensure that it speciﬁes the length of the

extended UCB in the ucbsize argument of the DPTAB macro:

DPTAB -,

UCBSIZE=UCB$K_XX_LENGTH,-

Figure 1–23 Unit Control Block (UCB)

UCB$L_FQFL* 0

UCB$L_FQBL* 4

UCB$W_SIZE*UCB$B_TYPE*UCB$B_FLCK 8

UCB$L_FPC 12

UCB$L_FR3 16

UCB$L_FR4 20

UCB$W_BUFQUO*UCB$W_INIQUO* 24

UCB$L_ORB* 28

UCB$L_LOCKID* 32

UCB$L_CRB* 36

UCB$L_DLCK* 40

UCB$L_DDB* 44

UCB$L_PID* 48

UCB$L_LINK* 52

UCB$L_VCB* 56

UCB$L_DEVCHAR 60

UCB$L_DEVCHAR2 64

UCB$L_AFFINITY* 68

UCB$L_XTRA 72

UCB$B_DEVCLASSUCB$B_DEVTYPEUCB$W_DEVBUFSIZ 76

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