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INPUT/OUTPUT PROVISIONS
.26.2 --
Device Independent
I/O
D (Bit 0) -- Oerault binary record format flag
Some
devices
cannot
receive
or
transmit
eight-bit data bytes.
For those types
Or
devices
a
special
record
format
has
been
designed
so that
binary records can be processed.·
Devices
that
can
process
eight-bit
data
can
process either type Or
record rormat.
The
uD"
bit
controls
the
default
record
rormat
to be used when dealing with ==binal'q='
'rec ords.
The
FMT ri
e
1 d of the IOCFDF
entry
in
th
e
IOCB
has
a
special value that will cause the default
binary record format to be
used
for
the
indicated
device.
If
the
liD" bit is set to one,
the default
record
format
will
be
the
ASClI-converted-binary
format
Conly if binary records are being processed).
If the
"0"
bit is
set
to
zero,
then
the
default
record
fOrmat
will
be
the
binar~
format (only if
binary records are being processed).
If
the
device
can
process
eight-bit data,
then the setting of the
"0" bit is independent of the device
typei
however,
ror
devices
~hich
can only process seven-bit data,
the
110"
bit must
be
set
to
one.
Otherwise,
the
device may respond unpredictably when binary data are -
being transmitted to it.
26.2, L 5. CDBVDT --
Valid data types
.
This byte of the CDB
is
an
extension
of
the
CDBDDF
entry.
It
contains
some
additional flags that govern the
types of I/O accesses that can be made on
the
device.
The
fo~mat
of the CDBVDT entry is shown below.
7
6
5
4
3
: N I
2
1
: B :
o
Not used
(=0)
Binar~
device rlag
Not used
(=0)
Non-file format flag
The
properties
controlled
by
the various bits of the
CDBVDT entry are explained below.
Page
26-07
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