User`s manual
DVlls
should
be connected
ahead
of
all Massbus
devices
on
the Unibus
and
behind unbuffered
NPR
devices such as RK05s.
DVlls
have placement
requirements similar
to
those for
DQIls.
If
both
DQ
II
sand
DV
II
s
are
used, place
the
units with
the
highest
baud
rate
first.
If
all
DVlls
have
16
lines
at
a
9600
baud
rate, a maximum
of
I
DVII
can
be
con-
nected with
the
following exceptions:
a.
Two
DVlls
can
be
used
on
a
PDP-l
1/40,
PDP-I
1/45,
or
PDP-II/50
with
no
disks.
b.
Two
DVlls
can
be
used
on
a
PDP-II/70
with
no
Unibus
disks.
For
lower speed lines, the maximum
number
can
be
increased proportionally. (Example: a
PDP-II/40
with 2400
baud
rate
lines
can
use four
DVlls.)
A
maximum
of
four DV
lis
can
be
placed
on
any sys-
tem because
of
address space limitations; the limita-
tions
are
based
on
NPR
access.
Interrupt
performance depends
on
the
operating system, pro-
tocol,
and
buffer lengths.
2.1.3 Interface Specifications and Signals
The
DVII
presents
two
unit loads to the
PDP-II
Unibus
and
also provides modem control
and
data
leads compatible with
EIA
RS-232-C
and
CCITT-
V24 specifications. EIA RS-232-C electrical specifica-
tions
are
listed in Table 2-1.
2.1.4 Interrupt Priorities and Address Assignments
2.1.4.1 Interrupt Priorities -
The
DVII
uses three
interrupt
vector addresses.
Interrupt
priorities for the
Data
Handling Section
are
selectable by means
of
a
priority plug
on
the
M7837 module.
The
priority plug
is preset
to
select BRS priority;
it
may
be
changed
to
select BR6 priority,
but
the diagnostic programs
expect BR5.
The
Modem
Control
Unit
is per-
manently wired
to
BR4
priority.
2.1.4.2 Interrupt Vector Address Assignment -
Com-
munications devices
are
assigned floating interrupt
vector addresses
as
follows:
I.
The
vector space
starts
at
location
300
and
proceeds
upward
to
776.
2-2
2.
The devices are assigned in
order
by type:
DCII;
KLII/DLII-A,
-B;
DPll;
DMII-
A;
DN
II;
DMII-BB;
DRII-A;
DRll-C;
PA611 Reader; PA611 Punch;
DTll;
DXII;
DLll-C,
-D,
-E;
DJII;
DHll;
GT40;
LPSII;
VT20;
DQII;
KWII-W;
DUll;
DUPII;
DVII
Data
Handling
Section/DVII
Modem
Conrol
Unit.
3.
If
any type device
is
not
used in a system,
vector assignments move down
to
fill
the
vacancies.
4.
I f additional devices are to be added
to
the
system,
they
must
be
assigned
con-
tiguously after
the
original devices
of
the
same type. Reassignment
of
other
type
devices already in
the
system may be
required.
(For
example, the vector for
another
DVII
would
be
after the existing
DV
II,
but
addition
of
a
DC
II
would
cause all
other
vector addresses
to
move
upward.)
Each device interrupt vector requires four address
locations (two words).
A further constraint is
that
all
vector addresses must end in 0
or
4.
The
vector
address
is
specified as a three-digit, binary-coded
octal
number
using Unibus
data
bits
0-8.
Because the
vector
must
end
in 0
or
4, bits I
and
0 are
not
speci-
fied (they
are
always 0) and bit 2 determines the least
significant octal digit
0 f the vector address (0
or
4).
2.1.4.3 Address Assignments -
The
DVII
is assigned
an
address
of
77S000. Additional
DVlls
would
be
at
77S04O,
77S100, 77S140, etc.
If
any
DMII-AAsarein
use, the
DVII
will follow them.
2.1.5 Environment
The
DVII
will operate in
temperature
environment
from 10°
to
50° C with a relative
h~midity
up
to
90%,
non-condensing. Power requirements
are
as follows:
Voltage
+S
-IS
+IS
Current
(Amperes)
21
1
O.S