Specifications
TABLE
6-1.
STATUS
TYP~
SUMMARY
D Code
Type
Status
0 Disk
adapter
file
register
data
1 Physical unit number
2
Poll
status
3 Select acknowledge
status
4 Drive echo input
data
5
Cylinder address
status
6
Current physical
sector
address
7
Sector and head address
status
8
Disk
adapter
status
9
Drive
status
word 2
A
Error correction code
pattern
B
Error correction code condition
status
C
Drive fault condition
status
D
Control unit
status
E Drive
status
word 1
F
Control unit echo input.
data
1833."
Cartridge
Disk
(COD)
Status
Bit
Status
0=1
Ready
96769450 B
Description
The device is available and ready
to
operate.
The drive becomes
not ready if:
• The disk pack is not in the
drive unit.
• The disk drive motor has not
reached
operating speed.
• The
read/write
heads
are
not in
the
operating
position.
• A fault condition develops in
the
drive.
Comments
Input comparable
to
select
file address output
function
Specifies physical number of
current
selected
logical
drive
Specifies response
to
selected poll condition
by
drive
number
(0
through 7 or 8 through
F)
Drive
select
status
Verifies
data
lines between control unit and drive
using
pattern
selected by echo function command
Last cylinder address used
by
disk
adapter
Current
sector
under
read/write
head
Current
sector
and head for function
This
is
the standard
status
word described above.
Status
of
selected drive
Error bits
00
through
07
used
by
ECC polynomial
processor
Status of
error
correction code used for polynomial
correction
Status
of
malfunctioning drive
Status of
selected
control unit
Valid only
after
direct
memory access read
or
write
command
Verifies command.
status,
and
data
paths between
disk
adapter
and control unit using
pattern
selected
by
control unit echo function command
The
status
condition is
affected
by
the
operating program only if
it
selects
a non-existent device
that
is
not ready.
1=1
Busy
Normally,
the
ready
status
bit
indicates
that
manual
interruption is required
at
the
selected
drive unit.
The
controller
is presently
performing
an
operation. The bit
is
set
by
accepting
the
following
command:
• Unit
select.
•
Bus
connect.
6-27