Table of Contents
Advertisement
IBM 1054 Paper Tape Reader
The
IBM
1054
Paper Tape Reader provides paper tape
input for
the
1800
system.
The 1054 (maximum of one
per
syste m)
operates
under direct control of the stored
program an
d
reads
I-inch
,
eight-track paper tape. The
maximum reading rate is
14.8 characters per second
.
Paper
tape
reading under program control is initiated
by
a control
command
issued
to the 1054. This
command
loads a character
into
an input
buffer
and
then moves the
paper
tape one
character
position. When the buffer has
been
loa
ded
with
a
character, an
interrupt
is
generated
signalling
the stored
program that a character is available
for rea ding into
main storage.
A
subsequent
read
command
from the
program reads the character
into main
storage
from
the buffer.
Paper Tape Initial Program
Load
If
there is
no 1442 on the system,
the 1054
is
used
for
initial
program load
(IPL).
The 1054 is forced into run
condition as a
result
of
pressing PROG LOAD
and operates
at its
maximum
speed
of
14.8
characters
per
second.
Data
words are
read into
main
storage,
starting
at
the location
specified
by
the
I-register.
Paper tape
channels 1 through 4
of each tape character
are
used
as
data
bits
for
assembly
in to
a
16-bit
word
during IPL. The
16-bit word
is assembled
in
the
paper
tape reader for transmission to main
storage.
When
a
word
is assembled, the
I/
O
channel
is
signalled and the
word is
transferred to
main
storage. The I-register
is then
incremented by
one.
IPL
continues
in
this manner until
a channel-5 punch
,
in other
than
a
delete
character,
is
detected
in the paper
tape. When this
channel-5
punch
is
detected,
IPL
is
terminated and the 1054
is stopped.
The I-register
is then
reset to
0000 and
the processor-controller
commences
execution of the
loaded
program. The paper
tape
character with
a
channel-5 punch
is not read
into
main
storage.
During
program
load
,
del
ete characters are recognized by
the 1054 and are not loaded
into the assembly
buffer.
Delete
characters
are
not recognized nor handled in
any
special manner
by
the 1054
except in IPL mode. This
allows a
leader
of
delete
characters to facilitate loading
the tape.
OPERATOR CONTROLS (Figure 8)
Figure 8.
1054
Operator Controls
16
IBM
1800
Operating Procedures
The Table R
elease
Key, when pressed
,
causes the tape
guide
to raise,
permitti
ng insertion or removal of previously
punched
tape.
The
Advance Wheel
permits tape to
be
moved forward or
backward while
maintaining proper
registration. Reading
does
not occur during this
movement.
The Tape
Tension
Lever
actuates a switch which signals a
not ready condition if too
much tension is placed on the
tape
as
it feeds through the unit.
The Tape
Presence
Contact
signals a not ready condition
when
the
reader
runs
out of
tape.
Advertisement
Table of Contents
