Specifications
1833-5
'Flexible
Disk
Drive
and
1865
Disk
Drive
Status
Bits
0=1
1=1
2=1
3=1
4=1
5=1
6=1
7=1
8=1
9=1
10=1
Status
Unit ready
Unit busy
Head loaded
Seeking
Reading/
writing
Interrupt
Interrupt
selected
DMA
parity
error
DMA
protect
fault
DMA
memory
address fault
Lost
data
96769450 B
Description
The disk is
at
running speed. The
initial seek
is
to
track
O.
The unit
is
busy with
data
trans-
fer on the seek operation. The
bit cleared
bv
the end-of-
operation, seek
"error. operation
aborted,
or
master
clear.
The head is automatically loaded
(brought with the proper
read/write
distance of the drive
surface) when a
data
transfer
begins. The head automatically
unloads if no
data
transfer
or
seek occurs within
six revolu-
tions.
The head is seeking as a result of
a seek com mand
or
automatic
seek
to
the next track. The bit
cleared
when
the
operation was
completed.
The unit is transferring
data
or
initializing. The bit clears when
the
operation completes or
aborts.
The unit became not busy, and
the
interrupt
was
selected.
It
was cleared by
interrupt
select/clear
or master clear.
The
interrupt
selected
status
en-
abIes the
interrupt.
It
sets
bit
5
at
the
end of operation.
It
is
cleared
by
interrupt
clear
or
master
clear.
The
direct
memory access
parity
error
status
detects
memory
parity
errors during write
to
disk
via
direct
memory access lines.
The
direct
memory access pro-
tect
fault
status
attempted
to
write
into
protected
CPU
memory with a request
initiated
by an unprotected command.
The
direct
memory access
memory address fault
status
attempted
to
write
to
a non-
existent
address in main
memory.
Direct
memory access has not
accepted
or presented
data
be-
fore the controller required
data
to
be moved. This
status
cannot
occur during buffered operation
since
data
is
transferred
to
the
controller buffer register one
sector
at
a time. Transfer
on
the
direct
memory access lines
is
not dependent on disk
rotating
speed.
Status
Bits
11=1
12=1
13=1
14=1
15=1
Status
Seek error
Data
CRC
error
Description
One of the following
errors
occurred:
•
No
address sync
was
found
within one second.
• Wrong
track
address for
transfer
• Cannot find requested
sec-
tor address
• Address cyclic redundancy
check
error
found
•
No
data
record or only de-
leted
data
records found
within one second
A
ttempted
transfers are aborted.
The controller and unit become
not busy. If the drive or con-
troller
error
caused the wrong
address, a seek to track
0 is
re-
quired for recovery.
The cyclic redundancy check
failed in the
sector
just read.
Deleted record The
current
sector
being read
has
deleted
the record sync code.
Protect
switch The flexible disk drive system
on
protect
switch is on, sampled
only
after
a
master
clear.
Controller busy The
data
transfer
logic of the
controller
is currently
in
use.
Attempted
data
transfers
are
rejected.
1843-1
Communication
Line
Adapter
Status
Bits
0=1
1=1
2=1
3=1
4=1
5=1
6=1
7=1
Status
Ready
Busy
Interrupt/
input
data
Interrupt/
output
data
Description
The power
is
applied.
Always
0
The
character
is ready for
trans-
mission
to
the CPU.
The receiver is ready for
char-
acter
t.ransm iss ion from the
CPU.
Error
interrupt
An
error
condition is
detected
ADT
on
input Auto-data
transfer
mode and
input mode
ADT
on
output Auto-data
transfer
mode and
output mode
Sync match During extended channel func-
tion transmission, the
data
matches the sync code.
6-29 I