Specifications

Data Structures
1.19 Unit Control Block (UCB)
Table 1–26 (Cont.) UCB Terminal Extension
Field Name Contents
UCB$L_TT_FBK* Address of fallback block.
UCB$L_TT_RDVERIFY* Address of read/verify table. Reserved for future use.
UCB$L_TT_CLASS1* First class driver longword.
UCB$L_TT_CLASS2* Second class driver longword.
UCB$L_TT_ACCPORNAM Address of counted string.
UCB$L_TP_MAP* UNIBUS/Q22–bus map registers.
UCB$B_TP_STAT DMA port-specific status.
The following fields are defined within UCB$B_TP_STAT.
TTY$V_TP_ABORT DMA abort requested on this line.
TTY$V_TP_ALLOC Allocate map fork in progress.
TTY$V_TP_DLLOC Deallocate map fork in progress.
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