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b
-
M Z
-
5600A
Check
:
illegal
command
,
desig-
nated unit
address,
etc.
Sector address
+
1
No
No
1
step seek
head
=
0, cylinder
=
+1
Yes
-
6
-
READ
INDEX
AM-
ENA
BLEO I
AM- FOlJND
READ-GA
T
E
3
~
I~
~
0000
:rn
.
.
I··,.
,
....
, ... ,,,,,
,,,,
,,,
,,,., ..
,.,,,,,,
D
ATAO
DATA
l
L__A
___j
3
Magnification of the A Part
I
I
I
I
0140
[Q]
'
0390
0640
,
,
.
, .
,
... , ,
m
,
,
, , . ,
,
,
,
,
, , ,
,
, , .
,
,
,
, ,
,
.. , , ,
, ,
.
. , , , ,
3-3.
Write Operation
In the data write operation, the ID read is first executed to
search the designated
sector.
On finding the des ired ID
field
,
the write gate is opened and writing is executed
.
Write data are transferred from the host to RAM
,
then from
RAM to NDC-840
,
where they are transformed to serial
data
.
As the ECC is generated by the ECC Generator, the
data are transformed into the MFM pattern and transferred
.._.,
t
o the disk. After completing the data
,
the generated ECC
(error correcting code) is transferred to the disk.
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