Specifications
Status
Bits Status
5=1
Alarm
6=1
7=1
8=1
6-16
No
compare
Protected
Checkword
error
Description
The alarm
status
bit indicates
that
one of the following
abnormal conditions occurred:
Not ready
Check
word
error
Lost data
Seek error
Address error
Storage parity error
Protect
fault
Any
output function clears the
bit. The not ready condition can
be changed
by
manual interven-
tion.
The data received from com-
puter core storage does not com-
pare with data read from file
storage during compare opera-
tion.
The
bit
is cleared
by
any output
function.
The controller is presently
reserved for or being operated
on
by the protected computer
instructions, or the drive unit is
protected
and may only be
accessed
by
protected computer
instructions.
The
con"troller is reserved for or
being operated
on
by a protected
instruction;
it
can be cleared by
a protected director function
that
has the release bit
set
in
A.
The drive unit is protected
by
the PROTECT switch
on
the
operators panel;
it
can then be
cleared
by
ehanging the
PROTECT switch to
its
off
posi-
tion
(down)
or
by
deselecting the
unit with a director function
that
has the proper
protect
code
set
in
A.
The controller logic has
detected
an incorrect checkword
in
data
read from file storage during a
read, compare, or checkword
check operation.
The bit is cleared
by
any output
function.
Status
Bits Status
9=1
Lost
data
10=1
11=1
12
13=1
Address error
Controller
seek error
Drive type
Storage
parity error
Description
The direct access bus of the
computer has not been able
to
keep
up
to
the file
data
transfer
rate
during a write, read, or
compare operation.
The bit is cleared
by
any output
function.
The controller has detected an
illegal file address received from
the computer, or the controller
has advanced the file address
beyond the limits
of
file storage.
The bit is cleared
by
any output
function.
The controller has been unable
to
obtain the file address selected
during a write, read, compare, or
check word check operation. This
error usually indicates a posi-
tioning error. The error can be
corrected
by
doing a
status
of
the drive cylinder, and com-
paring this with the cylinder
register (to find out
how
many
tracks and in what direction the
positioning error is from the
selected file address). The first
load address function following a
controller seek error moves the
cartridge disk drive positioner
without changing the cylinder
register and can therefore
correct
the positioning error.
The bit is cleared
by
any func-
tion
that
sets
the busy status.
An
856-2 drive is connected.
The controller has received a
parity error signal from the
direct storage bus while receiv-
ing
data
or control information.
If
the error is
detected
on con-
trol
information transfer, the
operation ends immediately.
If
the error is detected during
data
transfer, the operation ends
at
the end of the sector being
operated on.
The bit is cleared
by
any output
function.
96769450 A