Commodore 8250LP, SFD-1001 Technical Manual
Commodore
Disk Drive
Technical Manual
Model
8250LP
SFD-1001
These
documents
are
for
repair service
information
only.
Part
numbers
are
for
reference
only.
Only
parts
on
current
dealer
parts
list
are available.
No
license
is given
for
any
use
by
possession
of
these
documents
and
may
not
be
reproduced
in
any
form
without
the
written
approval
of
Commodore
Electronics
Limited.
C::
commodore
COMPUTER
CONTENTS
I.
GENERAL
rL
CAPACITY
m.
MEDIA
IV.
ENVIRONMENTAL
V.
RELIABILITY
VI.
POWER
VU.
DRIVE
VlII.
INTERFACE
IX.
SUGGESTED
GENERAL
CONTROL/DATA
TIMING
REQUIREMENTS
X. PHYSICAL OUTLINE
XI.
PARTS
LIST
(1)
I.
GENERAL
II.
Description
The
JU-570
is
a
1.
625"
High
(1/2
Hight)
doub
le-sided
double-clensi
ty
100
TPI
minifloppy
diskette
drive.
It
contains
a
band
actuator,
a
DC
direct
drive
motor,
bicompliant
read/write
head
geometry,
track
o
detector
index
detector,
write
protect
switch,
~/W
electronics
and
motor
speed
control
electronics.
CAPACITY
Sin~le
Density
Double
Density
A.
Encode
Method
n{
~tF1>1
B.
Unformatted
Bits/Diskette
4,000,000
8,000,000
Bits/!rack
25
,000
50,000
C.
Formatted
16
Records/Track
(Hard
or
Soft)
Bits/Diskette
2,621,440
5,242,880
Bits/l'rack
16,384
32,768
Bits/Sector
1,024
2,048
D.
Formatted
10
Records/Track
(Hard
or
Soft)
Bits/Diskette
3,276,800
6,553,600
Bits/Track
20,480
40,960
Bits/Sector
2,048
4,096
E.
Formatted
18
Records/l'rack
(Soft)
Bits/Diskette
2,949,120
5,998,240
Bi
ts/Track
18,432
36,864
F.
Transfer
Rate
Bits/Second
125K
250K
Bytes/Second
15.f)25K
31.
25K
III
~!E.DIA
Diskette
Mcr
recommended
Minidiskette
for
double-sided
double-density
double
track
dri
'.-e.
(
2)
Tracks
per
inch
per
surface
per
disk
Track
Location
track
36
radius
(Side
0)
(Side
1)
IV.
Et'JVIRONHENTAL
Operatin~
Ambient
Temperature
41°
to
115°F
5°
to
46°C
Relative
Humidity
20
to
80%
Ha.'C.
\{et
Bulb
BO°F
29.4°C
100
78
156
1.9166
in.
1.8333
in.
Shippii1~
_4°
to
HO°F
-20°
to
60°C
8
to
90%
48.682
nun.
46.566
[!I.ln.
Stora~e
_4°
to
122
c
F
-20°
to
50°C
8
to
90%
No
Condensation
Change
15°C
Change
should
allow
1
hour
for
diskette
to
stabilize
to
ne~
environment.
v.
RELIABILITY
Error
Rate
-
\'ihen
used
wi
th
~'CI
recommend
circuits
or
eqi
v.
Soft
read
errors
(2
retries
min.)
n
1
per
10~
bits
transferred
Hard
read
errors
1
per
10
12
bits
t.ransferred
Seek
errors
1
per
10
5
seeks
:-!edia
Diskette
insertions
Diskette
clnmpling
(With
rotated
spindle)
30,000
30.000
~iTBF
(~Iean
T ime
bet\~een
Fai
lures)
10,OOOH.
duty
cycle
25%
p~
(Preventativ~
~aintenance)
None
~rrTR
(;o!ean
Time
to
Repair)
30
minutes
Component
Life
5
years
~!edia
Life
:;
x
10
6
passes
per
track
(3)
VI.
PO\vER
VII.
DC
Voltages
+5.00
±
0.25
VDC
@
0.2A
typical
+12.00
±
0.60
VDC
@
1.2A
m~~.,
.75A
typical,
100
mV
p-p
ripple
BTU/Hr.
(1
watt
=
3.413
BTU/Hr.)
BTU
Typ.
Watts
Typ.
DRIVE
A.
~Iechanical
Seek
Settle
Time
Track
to
track
access
time
Drive
Motor
Start
Time
Rjlf
Head
Head
load
Radial
align./hysteresis
Azimuth
(-Iodulation
m~~.
Spindle
Speed
B.
~lour1ting
F:-on1:
Loading
42.7
12.5
18
ms
m~~.
Consisting
of
3
ms
track
to
track
seek
time
and
15
ms
settle
time
1
sec
m~"C.
17
±
:5
gr
70%
min.
33'
±
18'
20%
max.
300
RP~1
~
3%
Disket~e
Ver1:ical
(Side
1
left
or
right)
Yes
Disket~e
Horizontal
(Side
1
up)
Yes
Diskette
Horizontal
(Side
1 do",-n)
No
Top
Loading
:-;0
C.
Electrical
-
Readings
at
21°C
and
nominal
volta~e
unless
othen.ise
specified.
1.
Dri
ve
~Iotor
H3-'C.
stall
current
~t3-'C.
running
current
Typical
current
Start
time
2.
Stepping
:'1otor
Stepper
Motor/2
Phase
(12
V)
3.
Read/Write
Channel
Head
Resistance/1NDUCTANCE
Resistance
R\'i1
or
R\y-2
to
CT
Inductance
R\i
at
full
coil
Resistance
Erase
to
C.T.
Inductance
Erase
Performance
900
MA
400
HA
280
K.\.
1
sec
m3-'C.
1-35
320
-30
~1A
37
±
30%
ohms
2
±
3aYo
mH
8.0
_ 30%
ohms
3.3
_
30%
1J.H
Test
criteria:
Head
and
Carriage
Rotational
speed
300
rpm
Track
radius
at
track
77
Fre~uency
125
kHz
Load
pad
pressure
17
±
3
grams
',rri
te
current
6.3
::
0.2
M.A
p-p
Average
read
amplitude
after
writing
1.3
mv
p-p
min.
Resolu~ion
60%
min.
VIII.
I~T£RFACS
A.
Introduction
This
specification
describes
the
requirements
of
the
physical
and
electrical
interface
with
the
JU-570
Diskette
Drive
unit.
The
physical
interface
section
specifies
the
mechanical
requirements
as
well
as
lis~s
recommended
parts.
The
electri-
cal
interface
defines
the
functional
as
well
as
timing
relationships
required
of
each
I/O
pin.
(Fig.
1)
(5)
GV
5V
(NC)
GV
12V
GV
Gi"iD
-HOTOR
ON
TRACK·
ZERO
PH·E
TR..,l"CK·
ZERO
PHC
TR..\CK·
ZERO
LED
K
(KEY)
(NC)
STEPPER
COM
0
STEPPER
CO/>!
1
Sl-ID
-4
S?-ID
-1
S:-ID
-2
Sl-ID
-3
ACTIVITY
LED·..\.
ACTIVITY
LED·K
WRITE·PROTECT.PHE
~~ITE·PROTECT·PHC
I~uLX·SECTOR·PHE
INDLX·SECTOR·PHC
(NC)
I
(NC)
ide
0
GND
tEY)
R/WZ
COMMON
R/Wl
E~ASE
d
e
1
NC
ER.ASe:
R/,N
1
COMMON
R/W2
GNO
P1
..
1
2
3
45
6
7
8
9
10
11
12
13
1415
16
17
18
19
20
21
22
23
24
PZ
1
3
5
7
9
1 1
2
4
6
8
10
12
.
(HEn
)
(ORA)
SPINDLE
~!OTOR
(BLK)
CONTROL
PCB
(\,HI)
(\"HI)
(GRN)
r------
--~
~
~
~
r'\
'I
(YEt)
'~'ONll05
l
: t.:1\ :
I
~
!
~--------
-
(RED)
(RED)
fl"I.
(ORG)
r-
----<
-----c
~,
..
-
I
(BUO
I
I
,.-
(BRN)
I
:
STEPPER
~iOTOR
(YEL)
..
I ..........
(GRY)
'-_!V
____
(WHI)
(BLK)
(G&'l
)
(ORG)
(
RED)
Pi
(C:--lT
C:--l)
R/W
I
•
•
____
..r.
tCi\
'C)I
,---....
PN1190
ER
CORE
I
~
.~
~------------------~
I
n
R/E
CORE
ER
CORE
J
J
WRT.P.
IND.
LED
LED
-Q-J
PN1184
Side
0
Sid
e 1
P2 (HE.;'O CN)
Fi~.
1
The
Electrical
Interface
Schematic
Loading...