LQ(L-NL-NIO-1) IOcb/NOFF IOcb: I/O control byte (16 bits)
NOFF = NIO + NL + 12 (16 bits)
LQ(L-NL-NIO) IOW (1) first extra I/O descriptor word (if any)
...
LQ(L-NL-1) IOW (NIO) last extra I/O descriptor word
LQ(L-NL) link NL last reference link
...
LQ(L-NS-1) link NS+1 first reference link
LQ(L-NS) link NS last structural link
...
LQ(L-1) link 1 first structural link
LQ(L) next adr of the next bank in the linear str.
LQ(L+1) up adr of the supporting bank
LQ(L+2) origin adr of the supporting link
IQ(L-5) IDN numeric bank ID
IQ(L-4) IDH Hollerith bank ID (4 characters)
IQ(L-3) NL number of links
IQ(L-2) NS number of structural links
IQ(L-1) ND number of data words
IQ(L) status bits 1-18 user
19-32 system 25: drop bit
19-22 NIO 26: mark bit
IQ(L+1) first data word
...
IQ(L+ND) last data word
This layout requires:
DIMENSION LQ(999), IQ(999), Q(999)
EQUIVALENCE (LQ(9),IQ(1),Q(1))
---- Format of a short dead region ----
word 1: bits 1-16: NW, # of words, with 0 < NW < 12
17-24: NW again for redundancy
25: drop-bit set
26-end: zero
2->NW: dead words, content irrelevant