Sharp FDD-412A - Page 21

FDD412A/B
Table 2.7 Contents of IBM Data Format
Length
(Byte)
Position
Track
Position
Contents
46
(FF)
x
40B
+
(00)
x
6B
Gl
gap
CYLO
HD1
CYL1V76
HDO/1
92
|
(4E)
x
80B
+
(00)
x
12B
eal Ip LCzLO___HDO 1 (FC)
Specia
Other
tracks
4
(C2)
(C2)
(C2)
(FC)
62
CYLO HDO 1
2 (FF) x 26B + (00) x 6B
(AE) x 50B +:°(00) x 12B
(FE) Missing clock
(Al) (Al) (A1) (FE) Missing clock
(00) % (4C); Track number
(00) or (01); Head number
(01) (1A); Record (secotr
(00)=128B (01)=256B; data part length’
Check byte
(FF) x 11B + (00) X 6B
|) Other tracks
CYLO HDO | 1
Other tracks
TRACK All tracks
HEAD
All
tracks
|
tracks
tracks
tracks
All
tracks
(4E)
x
22B
+
(00)
x
12B
|_CYLO
HDO
(FB)
.or
(F8);
Missing
clock
Other
tracks
(Al)
(Al)
(Al)
(FB)
or
(Al)
(Al)
(Al)
(F8);
Missing
-clock
CYLO HDO
Other tracks 256
All tracks
(FF) x 27B + (00) x 6B
| TYP247 |
FM method
MFM method
Geer
Other
tracks
|.66
|
(4E)
x
54B
+
(00)
x
12B
TYP247 | (FF) _x 2478
(FF) 598B
Other tracks
2.5 Logic Operations
2.5.1
Sensor-Related
Operations
(1)
The
following
5
sensors
are
provided
inside
the
FDD
to
sense
various
portions
for
status:
Table 2.8 Names and Functions of Sensors
Detection : Relation to
Sensor
Name
Function
:
System Interface Signal
Photo- t iti
1
TRACK
00
fe)
ce
Detec
s
head
position
TRACK
OO-N
transistor status. :
oh ;
Photo- Detects a write-
Z
FILE
PROTECT
FILE
PROTECT-N
transistor
pas!
Photo-
inhibited disk.
Detects the single-
3
|
INDEX
1
Soaks:
d
,
;
INDEX-N
and
.
t
ded
k
:
|
transistor
sided
disk
index
hole
DISKETTE
Il
Photo-
Detects
the
two-sided
SENSE-N
INDEX
2
disk
index
hole.
‘Checks if the door is
closed.
transistor
Microswitch
DOOR SWITCH
~15—