BASF 6106 User manual

6106 SINGLE-HEADED
6108 DOU.BLE-HEADED

REVISION
RECORD OF REVISION
REMARKS
,
*
01
VS
Il
Valid for SN 0000 -/- 0400
,
,
02
VS 111
Valid for SN 0500 -/- 1300
l
03
VS IV
Valid for SN 2100 -/-
~
04
Corrections
05
Add. Model 6108
Va 1id for Dri ves with PCS":\T 88366
11

L IST 0 F C 0 N T E N T S
SECTION
PAGE SECTION
PAGE
1.
INTRODUCTION
1-1
1.1
Genera 1 1-1 2.2.8 Type of Heads
2-20
1.2 Related oocumentation 1-1
2.2.8.1 Read/Write Head
2-20
l.J
Description 1-1
2.2.8.2 Side Select Logic 2-21
1.4 Specification
Summary
1-2
2.2.9 Write Ci rcuits 2-22
1.5
Options Summary
1-4
2.2.9.1 Wr ite In it i ate
2-22
1. 5.1 Factory
Installed Option 1-4 2.2.9.2 Write Logic 2-22
1. 5. 2
Jumper Options 1-4
2.2.9.3 Erase Delay Logic 2-24
1.6 Recording
Media
1-5 2.2.10
Read Circuits 2-25
1.7 Recording Formats 1-5 2.2.10.1
Read Initiate and Read Block
2-25
1.7.1 FM Encoding
1-5
Diagram
1. 7.2 MFM Encoding
1-5 2.2.10.2 Read/Write Select 2-26
1.8
Track Format
1-6 2.2.10.3
Read Amplifiers and Filter 2-26
Network
1.8.1 Soft Sectored Track Formats 1-6 2.2.10.4 Active
oifferentiator and 2-27
1.8.1.1 Soft Sectored Track Format
1-6 Comparator
for Single Density with 2.2.10.5
Time oomain Filter and Crossover 2-27
16 Sec tors/Track ä 128 Bytes
oetector
1.8.1.2 Soft Sectored Track Format
1-9 2.2.10.6
Timing Diagram Read Circuits 2-28
for Single oensity
(9 Sec tors per Track ä 256 Bytes) 2.2.11 oC-Control
and Power On 2-29
1.8.1.3 Soft Sectored Track Format
1-10 Reset Logic
for
Double oensity 2.2.11.1
DC-Control 2-29
(16 Sectors per Track a 256 Bytes) 2.2.11.2
Power On Reset Logic
2-29
2.
THEORY OF OPERATION
2-1
2.1 Functional oescription
2-1
2.1.1 Drive Mechanism
2-2
2.1.2 Spindle and Front ooor Mechanism
2-2
2.1.3 Positioning Mechanism
2-3
2.1.4
Head Load Mechanism
2-4
2.2
Logic Description 2-5
2.2.1
Interface Logic 2-5
2.2.1.1
Input Interface
2-6
2.2.1.2
Output Interface
2-6
2.2.1.3 Jumper Options 2-7
2.2.2 Stepper Motor Control 2-12
2.2.3 Drive Motor Control
2-14
2.2.4 Head Load Logic 2-15
2.2.5
Track Zero oetector 2-16
2.2.6 Write Protect oetector 2-17
2.2.7 Index/Sec
tor- and Ready Detector 2-18
2.2.7.1 Index/Sector oetection 2-18
2.2.7.2 Ready Oetection 2-19
III

l IST 0 F C 0 NT E NT S
SECTION
3.
3.1
INSTALLATION AND OPERATION
Installat ion
3.1.1 General
3.1.2
Unpacking and Inspection
3.1.3 Connecting Cables
3.1.4 Connectors
3.1.4.1 DC-Connector
3.1.4.2 Signal Connector
3.1.4.3 Frame Connector
3.1.4.4 Interconnecting Diagram
3.1.5 Logic Levels and Termination
3.1.6 Connecting Configuration
3.1.6.1 Single Drive Configuration
3.1.6.2 Multiple Drive Configuration
3.1.7 Selection of the Desired Option
3.1.7.1 Selection Options
3.1.7.2 Head Load Options
3.1.7.3 In Use / Disk Change Option
3.1.7.4 Door Lock Options
3.1.7.5 Activity LED Options
3.1.7.6 Write Protect Option
3.1.7.7 Stepper Motor Switching
3.1.7.8 Jumper Matrix
3.1.8 Drive Mounting
3.1.8.1 Mounting Positions
3.1.8.2 Mounting Dimensions
3.2 Operation
3.2.1 General
3.2.2
Mini Disk Storage and Handling
3.2.3 Write Protect
3.2.3.1 Write Protect if notch open
(optional)
3.2.3.2 Write Protect if notch covered
(ECMAl
4.
4.1
4.2
4.3
4.3.1
4.3.2
MAINTENANCE
General
Too1s and Test Equipment
Checks, Adjustment and
Replacements
PCS Replacement
Spindle Drive
System
PAGE
3-1
3-1
3-1
3-1
3-2
3-2
3-2
3-2
3-2
3-2
3-4
3-4
3-4
3-4
3-6
3-6
3-6
3-6
3-6
3-7
3-7
3-7
3-8
3-10
3-10
3-10
3-11
3-11
3-11
3-12
3-12
3-12
4-1
4-1
4-1
4-2
4-2
4-2
IV
SECTION
4.3.2.1 Drive Motor and Drive 8elt
Checks
4.3.2.2 Drive Belt Tension Check
4.3.2.3 Drive Belt Replacement and
Tension Adjustment
4.3.2.4 Drive Motor Speed Check
4.3.2.5 Drive Motor Speed Adjustment
4.3.2.6 Drive Motor Speed Adjustment
using a Frequency Counter
4.3.2.7 Drive Motor Replacement
4.3.3 Positioning System
4.3.3.1 Track Adjustment Check
4.3.3.2 Track Adjustment Procedure
4.3.3.3 Adjustment Check for Optical
Track
Zero Switch
4.3.3.5 Track Zero Switch Replacernent
4.3.3.6 Head Carriage Replacement
4.3.3.7 Head Load Pad Replacement (6106)
4.3.4 Head Load Mechanism
4.3.4.1 Head Load ~olenoid Replacement
4.3.4.2 Head load Actuator Check
4.3.5 Read/Write Electronics
4.3.5.1 Jitter Check and Adjustment
4.3.5.2 Read Amplitude Check
4.3.6
Photo Transistors and LED's
4.3.6.1 Photo Transistor Replacement
4.3.6.2 lED-Replacement
4.3.6.3 Index Detector Adjustrnent Check
4.3.6.4 Index Detector Adjustment
4.4 Location of Testpoints,
IC's,
Potentiornenters and Connectors
Spare Parts
PAGE
4-2
4-2
4-3
4-3
4-3
4-4
4-4
4-5
4-5
4-6
4-7
4-8
4-9
4-9
4-10
4-10
4-10
4-11
4-11
4-11
4-12
4-12
4-12
4-12
4-13
4-14
5.
5.1 Attachment
I, Spare Parts for BASF 6106
5.2 Attachment 2, Spare Parts for BASF 6108

FIGURE
1 - 1
1 - 2
1 - 3
1 - 4
1 - 5
1 - 6
1 - 7
1 - 8
1 - 9
2 - 1
2 - 2
2 - 3
2 - 4 a
2 - 4 b
2 - 5 a
2 - 5 b
2 - 6
2 - 7
2 - 8
2 - 9
2 - 10
2 - 11
2 - 12
2 - 13
2 - 14
2 - 15
2 - 16
2 - 17
2 - 18
2 - 19
2 - 20
2 - 21
2 - 22
2 - 23
2 - 24
2 - 25
2 - 26
2 - 27
2 - 28
2 - 29
L IST 0 F I L L U S T RAT ION S
Model BASF 6106/6108
Mini-Disk-Drive
Flexible
Disk Construction
and Dimensions
FM-Enco
din9
MFM-Enroding
Address Mark Patterns
Soft Sectored Track Format
with 16 Sectors per Track
Simplified EDC Shift Register
Soft sectored
Track Format
with 9 Sectors per Track
Soft Sectored Track Format
fOI' Double Density (MFM)
PAGE
1-1
1-5
1-5
1-5
1-6
1-7
1-8
1-9
1-10
Block Diagram BAsF 6106/6108 2-1
Drive
Mechanism 2-2
Spindle
and Front Door Mechanism 2-2
Positioning
Mechanism 6106
Positioning Mechanism 6108
Head Load Mechanism 6106
Head Load Mechanism 6108
Interface Logic
Auto select Option
Radial Select Option
Auto Head Load Option
Selected
Head Load Option
Radial
Head Load Option
Door Lock Latch Option
Timing Diagram Door Lock
Latch Option
Disk Change Logic
Timing Diagram Disk Change
Logic
Stepper Motor Control
Stepper
Motor Timing Diagram
Drive Motor Control
Head Load Circuit Door Lock
Solenoid and Activity LED
Driver
Head Load Timing Diagram
Track Zero Detector
Track Zero Timing Diagram
Write Protect Detector
Index Detector
Ready Detector
Ready Timing
Track Geometry
Electrical Connection of the
Read/Write
Head
Side Select Logic
2-3
2-3
2-4
2-4
2-5
2-7
2-7
2-8
2-8
2-8
2-9
2-9
2-11
2-11
2-13
2-13
2-14
2-15
2-15
2-16
2-16
2-17
2-18
2-19
2-19
2-20
2-20
2-21
v
FlGURE
2 - 30 Write Initiate Timing
2 - 31 a Simplified Write Circuits
6106/6108
2 - 31 b Timing Diagram Write Operation
(Simplified)
2 - 32
2 - 33
2 - 34
2 - 35
2 - 36
2 - 37
2 - 38
Erase Delay logic
Erase Delay Timing
Read Circuits 6106/6108
(Simpl ified)
Read Initiate Timing
Read/Write Select Logic
Read Amplifiers and Filter
Network
Active Differentiator
and Comparator
PAGE
2-22
2-22
2-23
2-23
2-24
2-24
2-25
2-2 ~
2-26
2-27
2 - 39
Time Domain Filter and Crossover 2-28
Detector
2 -
40
2 - 41
2 - 42
2 - 43
3 - 1
3 - 2
3 - 3
3 - 4
3 - 5
3 - 6
3 - 7
3 - 8
3 - 9
3 - 10
3 - 11
3 - 12
3 - 13
5 - 1
5 - 2
Timing Diagram Read Circuits 2-28
DC-Control Logic 2-29
Power On Reset Logic
Timing Diagram Power On Reset
Shipping Configuration
DC-Connector
Interconnecting Diagram
Interface Logic Levels
Recommended Driver/Receiver
Circuit
Single Drive Configuration
Radial Select Configuration
Daisy
Chain Select Configuration
Part Locations
(Principal)
Mounting Specification
Flexy
Disk Loading
Write Protect Feature (ECMA)
Write Protect Feature (optionJI)
Parts
Breakdown 6106
Parts Breakdown 6108
2-2 g
2-29
3-1
3-2
3-3
3-4
3-4
3-4
3-5
3-5
3-9
3-10
3-11
3"12
3-12
5-2
5-3

l IST 0 F TAB l E S
TAßlE
PAGE
1 - 1 Specification
Summary
1-2
1 - 2 Factory
Installed Option 1-4
1 - 3
Jumper Selectable Options 1-4
2 - 1 Input Signals 2-6
2 - 2 Output Signals 2-6
2 - 3 Write Protect Jumpering 2-9
2 - 4
Sequence of the Stepper Motor
2-12
Signals
3 - 1
OC-Power Requirements 3-2
3 - 2
Recommended J1 Mating Connectors 3-2
3 - 3 Select Options Jumpering 3-6
3 - 4
Head load Option Jumpering 3-6
3 - 5
In Use Disk Change Option 3-6
Jumpering
3 - 6
Ooor Lock Options Jumpering 3-6
3 - 7 Activity
LEO-Option Jumpering 3-7
3 - 8 Write Protect Option Jumpering 3-7
3 - 9 Stepper
Motor Switching Option
3-7
Jumpering
3 -
10
Option Jumper Matrix 3-8
3 -
11
Flexy Disk
Loading
3-11
3 - 12
Flexy Disk Unloading
3-11
4 - 1 Standard Tools
and Test 4-1
Equipment
4 - 2 Special Tools
and Test 4-1
Equipment
5 - 1 Spare Parts
BASF 6106
5-4
5 - 2 Spare Parts
BASF 6108
5-7
5 -3
R/W PCB-88356
5-10
5 - 4
R/W PCB-88366
5-13
VI

SECTION 1
INTRODUCTION
1.1 GENERAL
This manual contains descriptive material and
procedures useful in installation, operation,
maintenance
and repair of the BASF Mini Disk
Drive Models BASF 6106 and BASF 6108.
1.2
RELATED DOCUMENTATIDN
Product- and Interface Specification
BASF 6106/6108 80 307-046
1.3
DESCRIPTION
The models BASF 6106 and BASF 6108 are very compact
random access data storage units, which utilize
a 5.25" Flexy Disk as storage medium. The BASF
6106 stores data on one side of the Flexy Disk,
the
BASF 6108 on both sides.
The Flexy Disk is rotated at 300 RPM yielding
a data
transfer rate of 125~000 bits per second
in
single density. Up to 125 kbytes of raw data
may be stored on a single recording surface in
single density, and twice as much in double
density.
Data capacity on all 40 tracks varies from
81.92 kbytes (BASF 6106, 16 sec tors at 128 bytes)
to 368.64 kbytes, so increasing capacity more
then four times by using the BASF 6108 with
9
sectors of 512 bytes each.
The mini disk drives are equipped with a DC-
controlled spindle drive motor, thus no AC-Power
is needed. Ceramic read/write heads with tunnel
erase are
used with-in the BASF 6106/6108 to ensure
reliable data recording.
The heads are positioned with a fourphase DC-
stepper motor actuator, utilizing a spiral wheel
which provides precise location of the read/write
head or heads on the track.
Applications for both types of mini disk drives
comprise
word processing and text editing systems,
program storage for mini and micro computers,
"inte
11 igent" desktop ca1 cu 1ators and the hobby
micro computer market.
FIGURE 1 - 1 MODEL BASF 6106/6108 MINI DISK DRIVE
1 - 1

1.4 SPECIFICATION SUMMARY
Acomprehensive list of principa1 specifications for model BASF 6106 and model BASF 6108 is provided
in tab1e 1 - 1.
PER F 0 R MAN C E S P E C I F I C AT
ION S
CAPACITY BASF 6106
(single sided)
Unformatted Single Density
per
Disk 125 kilobytes
per Surface
125 kilobytes
per Track 3.125 kilobytes
Formatted
(16 Sectors/Track)
per
Disk
per Surface
per
Track
per Sec tor
TRANSrER RATE
LATENCY
Maximum
Average
ACCESS TIME
81.920 kbytes
81.920 kbytes
2.048 kbytes
128 bytes
125 kilobits/s
200 ms
100 ms
Track to track positioning 12 ms
Average 240 ms
Settling Time max. 48 ms
Head Load Time
max. 35 ms
Drive Motor Start Time max.650 ms
Doub 1eDens ity
250 kilobytes
250 kilobytes
6.250 kilobytes
163.840 kbytes
163.840 kbytes
4.096 kbytes
256 bytes
250 kilobits/s
F U " C T ION A L S P E C I F I C A T
ION S
BASF 6108 (double sided)
Single Density
Doub 1eDen5 ity
250 kilobytes
500 kilobytes
125 kilobytes
250 kilobytes
3.125 kilobytes 6.25 kilobytes
163.840 kbytes 327.680 kbytes
81.920 kbytes 163.840 kbytes
2.048 kbytes 4.096 kbytes
128 bytes 256 bytes
125 kilobits/s 250 ki10bits/s
BASF 6106 BASF 6108
Single Density
Rotationa1
Speed
300 RPM.:!:. 2,5 %
Recording Density
3979 BPRAD
( inside Track)
(2768 BPI)
Flux Densitv
7958 FTPRAD
(5536 FCI)
Track Density 48 TPI
Track Radius
Track 00 57,15
mm
Track 39 36.5125 mm
Encoding Method FM
Media Requirements BASF F1exy Disk
5.25"-1
+) On Side 1, Side 0 see 6106
Track radius 1 is 2. 1167 mm
smaller then track radius O.
Double Density Single Density
Double Density
300 RPM .:!:. 2,5 %
300 RPM .:!:. 2,5 % 300 RPM .:!:. 2,5 %
7958 BPRAD 3979 BPRAD
7958 BPRAD
(5536 SP!)
(2768 BP!)
(5536 BP!)
7958 FTPRAD
7958 FTRAD
7958 FTPRAD
(5536 FCI)
(5536 FC!)
(5536 Fe I)
48 TPI
48 TPI
48 TPI
+) +)
57,15 mm
55,03 mm +) 55.03
mm +)
36.5125 mm
34.3958 mm
34.3958 mm
MFM
FM
MFM
BASF F1exy Disk BASF F1exy Disk BASF F1exy Disk
5.25"-10 5.25"-2 5.25"-20
lABLE 1 - 1 SPECIFICATION SUMMARY (continued)
1 - 2

P H Y S I C ALS P E C I F I C A T ION S
Environmental
limits
Ambient temPerature on disk surface (operation)
Relative humidity
Maximum wet bulb
DC-voltage requirements
Power dissipation
Mechanical dimensions:
Width
Height
Depth
Wei ght
R E L lAB I L I T Y
MTBF
Unit life time
MTTR
Error rates:
Soft read errors
Hard read errors
Seek errors
S P E C I F I C AT ION S
ME 0
lAS P E C I F I C AT ION S
10
0
to 50
0C
(50
0F to
120
0
F)
20 % to 80 %
29
0C
(84
0F)
+ 12 VDC + 5 %
+ 5 VDC + 5 %
0,7
A+)
max. 100 mVpp ripple
0,5 A
max. 50 mVpp ripple
+) motor starting current
max. 0.65 Afor max. 50 msec
head load start current
0.7 Afor
50 msec
10.0 Watts operating
4.0
Watts stand by (motor off)
7.5 Watts motor on and deselected
146.1
mm (5.75 inch)
53.5
mm (2.11 inch)
19o.o
mm (7.48 inch)
1.4 kg
10000 POH under typical usage+)
5 years
30 minutes
1 per
10
8
bits read
1 per
10
11
bits read
1 per
10
6 seeks
+) Duty cycle of Spindle Drive Motor: ~% of POH
Jacket 133.3 mm (5.25 inch) square
Disk 130.2 mm (5.125 inch) diameter
Center hole 28.57
mm (1.125 inch) diameter
TABLE 1 - 1 SPECIFICATION SUMMARY
1 - 3

1.5 OPTIONS SUMMARY
The following tables list the options of the
ßASF 6106 and. ßASF 6108 Mini Disk Drives.
1.5.1 FACTORY INSTALLED OPTION
Option Function
Door Lock
Lacks the fant door under
Solenoid control of the users
soft-
ware.
TAßLE 1 - 2 FACTORY INSTALLED OPTION
1.5.2 JUMPER OPTIONS
The following options are selectable by jumpers
on the PCß. Refer to Table 3 - 10 for jumper
option matrix.
Option
RADIAL
SELECT
AUTO SELECT
HEAD LOAD
IN USE
Function
Allows the connection of
three
mini disk drives to
the hast system.
Each drive
has its own address (0,1,2)
selectable by jumper.
The interface is always
enabled (drive is always
selected).
The SELECT-lines are not
used.
Loading of the head can be
accomplished in three modes:
• Selected Head Load
(INT.SELECT- HEAD LOAD)
• Auto Head Load
(INT. SELECT)
• Radial Head Load
(HEAD LOAD)
The head will be loaded only
if the inserted mini disk
rotates.
Pin 34 of the interface is
used as IN USE input signal
and controls the door lock
solenoid
and the activity
indicator.
If this option is used the
disk change option
must be
disabled.
Option
OOOR LOCK
LATCH
OISK CHANGE
ODOR LOCK
ACTI V ITY
INOICATOR
OPTIONS
WRITE
PROTECT
OPTION
STEPPER
MOTOR
SWITCHING
Function
Allows locking of the door
withoui maintaining the
IN USE signal activated by
storing the state of the
IN USE-signal into the IN USE-
flipflop. Ta use this option
the
IN USE-option must be
jumpered.
Notifies the hast system
that the mini disk has been
changed. If this option is
used, the IN USE-option must
be disabled.
Locking of the door can be
accomplished as follows:
1.
by the IN USE-signal
2.
by the IN USE-FF
(ODOR LOCK LATCH)
3.
if the drive is selected
(1/0
ENA activ)
4.
if the head will be loaded
(HOLOADENA activ)
5. if 1.
or 3. is true
6.
if
l.
or 2. or 3.
is true
7. if
l.
or 4. is true
8.
if
1. or 2. or 4. is
true
The lighting of the activity
LED is selectable by jumper
to one of the following
conditions:
• the
head is loaded and the
drive
is ready
• the
door is locked and the
drive
is ready
Allows protection of the
mini disk against overwrite
if the write protect notch
is closed (ECMA, Shugart).
The stepper motor is switched
on .nd off together with the
drive
motor if a jumper is in-
serted. If the jumper is not
inserted, the stepper motor
will be enabled as lang as
power is supplied.
TAßLE 1 - 3 JUMPER SELECTAßLE OPTIONS
1 - 4
i
/

1.6 RECORDING MEDIA
The BASF mini disk drives use a removable
130 mm (5.25 inch) diameter flexible disk as
storage media. Fig. 1-2 shows 'construction
and dimensions of a typical 5.25" Flexy Disk.
The recommended recording media is:
formodel BASF 6106 mini disk drives:
single dens ity:
double density: 5.25"-1
5.25"-1 D
for model BASF 6108 mini disk drives:
single density:
double density: 5.25"-2
5.25"-2 D
The Flexy Disk is an oxide coated flexible
disk enclosed in a protective plastic
envelope. The protective envelope contains
apertures
for head contact, index detection,
write protect detection and drive spindle
loading.
The write protect notch is used to protect
the written data on the Flexy Disk (see 2.2.6
Write Protect Detector).
St:ALEIl
t'Kon:CTI vt:
.lACKET
SI' 1NOLEI
111111
.\t,U:SS
__ ----133,3 81111
R I
I"'l./
~ \
/
r
HYLAR OlSK
TRACK 00
/
FIG. 1 - 2
/'
/"
---
.......
........
Q)
/\,./ __ ---;.~_lNDEXI
SECTOR
IIOLE
-
LINER
/
/"
FLEXIBLE DISK CONSTRUCTION
AHD DIMENSIONS
lNDEX
HOLE
TRACK 39
1 - 5
1.7 RECORDING FORMATS
The format of the data recorded on the diskette
depends on the host system. There are two encoding
schemes used:
• FM (Frequency Modu 1ati on)
for single density
•
MFM (Modifieo Frequency Modulation)
for double density.
1.7.1 FM-ENCODING
This scheme utilizes clocks to define bit cell
times. The presence of a flux reversal between
clock pulses i5 defined as a "one" bit. The
absence of a flux reversal between clocks is
defined as a "zero" bit. On the write data and
read data interface lines between disk drive and
host system every pulse represents a flux re-
versal on the diskette.
8 jJsec
BITCELL
~-I
, i
OATA I' I'I ' 10 I ' I0 I 0 I0 I'I
I I I I I I 1 I 1 I
I I l-j8jJ
s
t- I I I I I
Il4jJ~11111111
I lir: I 1 I 1 I I
WRITE OATA I1IIIII 'al •I 'a'
COCOCOC COC C c eoc
FIG. 1 - 3 FM-ENCODING
1.7.2 MFM-ENCODING
Aflux transition is always recorded at the center
of the
bitcell for each Hone" data bit. No flux
transition is recorded for a "zero" bit unless it
is not followed by another "zero" bit. In this
case the flux transition is provided at the end
of the first bit cel,o
4 jJsec
BITCELL
DATA l,h tj
01
1
10
10 10 I' I
I I I I I I
I I I f'S~f'S~ I I
I I I I I -t4jJSl-- I
WRITE OITIl. I , , I ,
o 0
FIG. 1 - 4 MFM-ENCODING

1.8 TRACK FORMAT
The tracks of the F1exy Disk may be formatted
in
numerous ways, depending on the formatter
of the host system used.
The BASF mini disk
drives
write and read hard or soft sectored
track formats.
1.8.1 SOFT SECTORED TRACK FORMATS
In a soft sectored track format the user may
record one 10ng record or severa1 sma11er
records on a track. The most common soft
sectored track formats are described in the
fo110wing chapters.
(The designer should also consider national
and international standards for data inter-
change ).
1.8.1.1 SOFT SECTORED TRACK FORMAT FOR
SINGLE DENSITY
(16 sectors/track ä 128 bytes)
This format
is shown in Fig. 1-6. It is similar
to the IBM-format.
The beginning of a track is indicated by a
physical index pulse.
Every record is pre-
ceded
by a unique record identifier. Record
identifiers and data fie1ds are separated by
gaps. The gaps are necessary to allow updating
of a data fie1d without disturbing adjacent
fie1ds.
INDEX GAP
This gap starts with the index pulse and is
16 bytes in 1ength. It is not affected by any
update write process.
IDENTIFIER GAP
This gap consists of 11 bytes FF and may
vary slightly in length after the data field
has been updated.
DATA GAP
This gap separates the data fiel d from the
fo110wing ID-fie1d and is nominal1y 27 bytes
in 1ength.
It will vary slightly in length
after the data fie1d has been updated.
TRACK GAP
The gap between the last data fie1d and the index
pulse
is defined as Track Gap. It varies slightly
in 1ength. due to write freqyency and disk speed
tolerances. It is nomina1ly 101 bytes in length.
ADDRESS MARK (AM)-BYTE
The soft sectored track format needs unique bit
patterns to identify the beginning of ID and
Data Fie1ds for synchronizing the deserializer
circuit in the host system. The unique bit pattern
is ca1led Address Mark (AM). AM-patterns do not
contain clock
bits in all bit cells (allother
data bytes must have c10ck bits in every bit cell!).
There are three different AM-patterns used:
•
ID-AM
• DATA-AM
• DELETED DATA-AM
in front of an ID-Field
in
front of a Data Fie1d
in
front of aDeleted
Data Field
I BYTE
10 -AM:
f7SC
6 C
s C4 C
3 S
C, .~ 8
••
,., ,., ,.,
•I ••
SEI' CLOCK
(C7)
" "
..
,
,.
..
"
08
°7
°6
Os
°4
0)
Ll.!
SEP DATA
(FE)
I I I I I I I
DATA -
AM:
I
Ir
C7 C
6 Cs
C4
c)
I
1'8 r2
CI
IS
I I
,.,
....
.,
••I I
SEP CLOCK
(Cn
J;
..
I,
II ..
08 07 06
05
If.
°2 ,
°ll
SEP DATA
(F8)
I'
I I I I I I:
I
I I
DUETEn DATA -MI: I
fll
C7 c,. C5
Cf.
C)
'2
CI le 8
I I
,., ,.,
1"\ I I I •
SEP CLOCK
(c1)
I.
" "
,
Ir A,
Os
0,
°6
Os
()4
!lEP DATI.
CFS)
I I I I I
FIG.
1 - 5
ADDRESS MARK PATTERNS
1 - 6

SECTOR IDENTIFIER
The sector identifier consists of the identifier
mark, the address identifier and the EOC pattern.
IDENTIFIER MARK
This field comprises 7 bytes (see Fig. 1-6).
The 6 bytes of zeros in front of the address
mark byte are for synchronisation of the data
separator in the host system.
The ID-AM-byte
contains a data pattern of FE where the clock
bits C6, C5 and C4 are missing as explained
before.
AOORESS IDENTIFIER
The address identifier comprises the following
6 bytes:
TRACK ADDRESS (TRK)
This byte represents in binary notation the
track address
from 00 for the outermost track
to
39 for the innermost track.
SIDE ADDRESS (SID)
Represents in binary notation the sioe address
(00 or 01) of the mini disko
SECTOR ADDRESS (SEC)
Represents in binary notation the sector address
from 01 for the 1st sector to 16 for the last
sector of a track.
SECTOR LENGTH (LEN)
This byte identifies the length of the data field
as follows:
00:
128 bytes
01:
256 bytes
02:
512 bytes
03:
1024 bytes
EDC-BYTES (EDC)
These two bytes are hardware generated from the
host system
by shifting serially the bits of the
sector identifier starting with the ID-AM and ending
with the 4th byte of the
sector identifier through
a
16-bit shift register described by the generator
polynominal :
(For
more details read chapter EDC-implementation!)
SECTOR IOENTIHER IDF.NTIFIER GAP FIRST DATA BLOCK OATA BLOCK GAP LAST OATA BLOCK OATA BLOCK GAP
13 BYTES 11 X FF 137 BYTES 27 X FF 137 BYTES 27 X FF
1 si :öector
j--1-
BIDEX PULSE
V,C
6
I BYTE
'i ls
SECTOR IDE~TIFIER:
ID - AM:
Cs C4 S S
I I n "
...
I I I I
sn
CLOCK
(c7)
11
"
..
, ! ,
I.
"
OB
°7 06 05 04 °3
l2
SEP OATA
(FE)
I I I I I I I
'--v---J
ID-AH
I
I
DATA
BLOCK:
DATA -AM: I I
'C C7 C
6 Cs
C.
C3
'2
C,
~
,8
S
DATA
FIELD
I 2 8 B Y T E S
I I "
...
" I 1 I I
SEI' CLOCK
(C7)
I:
"
I.
II II
De
D7 D6 Os
D2
I
1.\
01.
SEP OATA
(FB)
I I I I 1 I
I:
~
,
DATA-AH I
I
I
I ) OATA
PATTERN
• I
DELETED DATA - AH:
I
2)
CLOCK PATTERN
•
OELETEO AM
pS
f'8
C7
ct. Cs
Cf,
C3
<lz
CI
le
S
1 I n
...
i1
1 1 1 •
SEP CLOCK (c1>
11
..
I,
,.
DS
0]
D6 DS
D.
SEP DATA
(FS) 1 I I I I
FIGURE 1 - 6 SOFT SECTORED TRACK FORMAT WITH 16 SECTORS/TRACK FOR SINGLE DENSITY (FM)
1 - 7

DATA BLOCK
The data block contains the data mark, the data
fie1d
and the EOC-bytes.
DATA MARK
This fie1d comprises 7 bytes (see Fig. 1-6).
The 6 bytes of zeros in front of the data
address
mark are for synchronisation of the
data separator
circuit in the host system. The
data address mark byte contains FB in front of
anormal data fie1d.
When adeleted data fie1d
fo110ws, F8 must be written. The c10ck pattern
of the data address mark is C7 (C6, C5 and C4
missing) .
DATA FJELD
This fie1d comprises 128 bytes. If it comprises
1ess than
128 bytes, the remaining positions
sha11 be fi11ed with zeros.
EDC-BYTES
These two bytes are hardware generated by the
host system
by shifting seria11y the bits of
the data block starting with the Oata-AM and
ending with the last byte of the data fie1d
I'\.. !cl
I----I~--
through a 16-bit shift register described by the
fo11owing generator polynominal:
EOC-IMPLEMENTATION
Fig. 1-7 is a simp1ified 10gic of a shift register,
which may be used to generate the EOC bytes.
Prior to the operation, all positions of the shift
register are set to ONE. Input data are added
(exc1usive OR) to the contents of position C
15
of
the
register to form a feedback. This feedback in
turn
is added (exc1usive OR) to the contents of
position C
4
and position C
11
.
On shifting, the outputs of the exc1usive OR gates
are entered
into positions CO' C
5
and C
12
respec-
tive1y. After the
last data bit was added, the
register is shifted once more as specified above.
The register then contains the EOC bytes. When
further shifting is to take p1ace during the writing
of the
EOC bytes, the contro1 signal inhibits ex-
c1usive
OR operations.
To check for errors when reading, the data bits
are added into the shift register in exact1y the
same manner as they were during writing. After the
data the
EDC bytes are also entered into the shift
register as if they were data. After the final shift,
the register contents will be all ZERO if the record
does not contain errors.
eONTROL
OUTPUT
tor EDe
writing
INPUT
FIGURE 1 - 7 SIMPLIFIED EOC SHIFT REGISTER
1 - 8

1.8.1.2 SOFT SECTOREO TRACK FORMAT FOR SINGLE
OENSITY (9 SECTORS/TRACK ä 256 BYTES)
In this format, which is shown in Fig. 1-8, each
sector contains 256 bytes.
I
1---------- Ist SECTOR
.r--L
x + Y + Z • 204 BYTES
INDEX PULSE
SECTOR IDE~TIFIER:
L-.---J
ID-AM
DATA BLOCK:
DATA
FIELD
2 5 6 B Y T E S
~
DATA-AM
I )
DATA PATTERN
2)
CLOCK PATTERN
• DEUTED
AM Fa
LAST DATA BLOCK DATA BLOCK GAP
256 BYTES (32+Y) X FF
9th SECTOR --I
10 -AM:
sn CLOCK (C7)
SEP DATA (FE)
OATA -AM: I
Ic C7 C6 Cs c4 C3 '2
I 8
I I
,., ,.,
'1
I I
SEP CLOCK
(C7)
I: " "
.. I.
Da
D7 D
6 D
s
Pt.
D2
SEP DATA
(FB) I I I I 1 I
I
DELETED DATA - AH:
~
C7
Ce Cs
Ct.
C3
C2
1 I n
.., ..,
1 I
SEP CLOCK
(c1>
' ,
I,
'I
.. .. ..
D8
D7 D6 DS
D4
SEP DATA (F8) I I I I I
FIGURE 1 - 8 SOFT SECTOREO TRACK FORMAT WITH 9 SECTORS/TRACK
1 - 9
I
I
CI
~8
I I
I
DI
I
I:
I
I
I
I
CI
IC
1
.8

1.8.1.3 SOFT SECTORED FORMAT FOR DOUBLE DENSITY
(16 Sec tors a 256 bytes)
On double sided diskettes for double density
track 0
on side 0 is recorded in FM. For
this track only the previous described track
format for single density
is valid. All other
tracks
on the diskette are recorded in MFM.
Far these tracks the following track format
will be valid (see Fig. 1-9).
The content of the data blocks is doubled to
256 bytes. In MFM recording the bit density is
also doubled. the sector count will be the same
as in single density format (1.B.1.1). The meaning
of the different fields a~ the generation of the
EDC-bytes are the same as in single density re-
cording.
Only the address mark pattern is changed
as shown in Fig. 1-9.
INOEX GAP
so x I.E
12 • 00 3. C2 1) IFC 150 dE 11 MI551NG CLOCK TRANSITIONS BETWEEN BITS S ANO l..
----::::_-'-- -
1 ____ _
I -_ --- __ _
I --_ --_
t---
1
BYTE----i ' --- -----
I C2 1 C2 C2 --- FC ----
11 11 101010 101 1 10 11 11 10 1010 10 11 10 11 11 101010 101 1 I"J 1 11 11 11 11 11 101 rJl
INOEX -AM
Os 07 Cs CL C3 02 OB 07 Cs CL C3 02 Os 07 Cs CL C3 02 Da ~ CI:, Dt. D:J 02 Cl Cs
I I I n I I I I I n I I I I I n I I I I I I I I I I
SECTOR 10ENTIFIER
71 MISSING CIOCK TRANSITIONS BE TWEEN BITS 4 ANO 3
10-AM·
1 -~----
I ----:::---- ___ _
I Al Al Al --- f'E ---:-\
11101110101010111'10111010101:'1111101110101010111'11111111111110,
Os 05 CI. C3 C2 0, Os 05 CI. C3 C2 01 Os 0" CI, C3 C2 01 Os 07 Cf; Os 01. 03
02 Ca
I I Inlll I Inl I1 I Inl .11111111
OATA BLOCK
OATA
-AM
OATA FIELO
255 BY rES
2) MISSING CLOCK TRANSITIONS BETWEEt~ BITS 4 ANO 3.
110ELFTFU RFCORO FB
I --------
I
----.-------
--
-- --
I --__ --- __
I Al Al Al -- FB ---_
1'10IlI01010101111101'101010101,1'10ilI0IUI010~'I'I'I'111011111
.
lOs 06 CL C3 C2 01 08 Dr; CI, C3 (7 01
1lfl llr,
CI, [3 C7 III lltj 11'1 lle, Os 111. 07 U,
11 I I n I I I I I nI I I I I n I I I I I I I I I
I
I
I
1
OELETED OATA-AM. Al Al Al FS
1110111010101011111011101010101111101110101010111,111111111010101
OB
I
FIGURE 1 - 9 SOFT SECTORED TRACK FORMAT FOR DOUBLE DENSITY (MFM)
1 - 10

2.1 FUNCTIONAL OESCRIPTION
The models 6106 and 6108 comprise the following
mechanisms and functional circuits (see Fig. 2 - 1).
Functional Circuits:
• Interface
• Drive Motor Control
Mechanisms:
• HEAD LOAD-, OOOR LOCK- and ACTIVITY LEO- Driver
• Drive
Mechanism
• Track Zero Detector
• Spindle
and Front Ooor Mechanism
• Write Protect Oetector
• Positioning
Mechanism
• Index / Ready Oetector
•
Head Load Mechanism
• Read / Write Circuits
• OC- Control and Power On Reset LOGIC
SELEC T 11
SELECT 21
SELECT 31 _
WRITE DATA I
WRITE GATE!
SIDE SfLHTI
I
N
P
U
T
o IRECTION
/NI
STEPI
I
N
T
f
R
F
A
C
IN USE I
(oploona
11
E
HEAD LOADI
MOTOR ON I
• SIOE SELECT LOGIC
UD E NA
WRITE INHIBIT
R(ADI
I-f--~ WRITE WRT (URRENT or RD PLAYBACK
CIRCU ITS [RASE
H--""I (URRENT
SIDf
HI-_-=S:;.:ID:..:E=--.:I _____ ""I SELE er
LOGIC
PHASE 1
S TEPPER
~I---<-t MO TOR
~I----<_ (ONTROL
3
4
~:dnCT ~rgS~R
ODOR LOCK SENSOR ~
~LENOID 0 \ ~
snPPER
MOTOR
I ~:-.. (<I ~ ZERO L.
I .... ~ LIGHT-
TRACK
ZERO
ETECTOR
I,pl"~,, i "L1~1~IT\:~ ~I ~~ r, ~TRACK
ODOR LOCK OOOR LOCK I .... NN ~- _~RIER...NC '--
ENA ANO ~ ~ ~I.ft
AUIVI TY ~~- ()!:!.I.!...--C':':':::"::.J
IEAO LOAD DRIVER R/W
[NA HEÄÖ-- HEAO 0 -MOTOR
~ ~~~SER HEAD LOAD
SOLENOID
DRIVE
HH_""I
MOTOR
(ONTROl
f--
INDEX J
READY
L-----------I
OETE
(TOR
INDEX
WRT. ERASE CURRENT
• sv oc
• 12V oe
1
CJl~ROL
AND
POWER ON
RESET
L- ____________ ~ WRITE
PWR ON RESET
PROTECT
OETHTOR
FIGURE 2 - 1 BLOCK DIAGRAM BASF 6106/6108
2 - 1
I
E ADY
o
U
T
P
U
T
I
N
T
f
R
F
A
(
E
REAO
DATA I
TRACK OQl
INDEXI _
READYI
D ISI<
CHANGEI
(optlon~11
WR ITE
PROTECTI

2.1.1 DRIVE MECHANISM
The spindle is rotated at 300 rpm by a DC drive
motor. Rotation of the spindle
is provided by a
belt and pulley. The drive motor is started and
stopped by the interface signal MOTOR ON.
The ratio between motor and spindle speed is
approximately 7:1. The drive mechanism is shown
in Fig. 2 - 2.
2.1.2 SPINDLE AND FRONT ODOR MECHANISM
The main parts of this mechanism are the drive
hub, the centering cone, the centering cone
expander
and the front door with pressure arm
and door latch (see Fig. 2 - 3). For loading,
a
diskette is inserted and the front door
pressed.
The pressure arm moves down, the
centering cone enters the Flexy Disk. Just
before the centerlng cone reaches the full
down position, the centering cone expander is
FRONT OOOR (closed)-----1'.
DOOR LATCH
DRIVE MOTOR
SPINDLE DRIVE
PULLEY
FIGURE 2 - 2
SPINDLE DRIVE HUB
DRIVE MECHANISM
activated and expands the centering cone which grips
the inner diameter of the Flexy
Disk to ensure correct
alignment. The door latch is activated and holds the
front door in a closed position. For un.loading a disk,
the
front door must be pressed again. The door latch
opens and the pressure arm is moved upwards by aspring.
The centering cone and centering cone expander also move
upwards and disengage the mini disk from the drive hub.
PRESSURE ARM
? - 2
CESTERING CONE EXP~~DER
I
CENTERING CO:\[
I
I
!
I
DRIVE Hl'B

2.1.4 HEAD LOAD MECHANISM
The head load mechanism comprises
(see Fig. 2 - 5):
•
Head Load Solenoid
•
Head Load Actuator
HEAD LOAD PRESSURE ARM
R/W HEAD
HE AD LOAD PAD
HEAD LOAD ACTUATOR
HEAD LOAD SOLENOID
R/W HEAD 0
R/W HEAO 1
When the head load solenoid is energized,the head load
actuator releases the head load pressure arm of the
carriage assembly. On the single sided mini disk drive
(BASF 6106) this causes the mini disk to be pressed
against the
read/write head by the head load pad.
On the double sided mini disk drive (BASF 6108) the
F1exy Disk is pressed against the bottom head (HEAD 0)
by the upper head (HEAD 1) mounted in the pressure arm.
The pressure foam on the head load actuator stabi1izes
the F1exy Disk. When the head load solenoid is deener-
gized,the head load actuator is 1ifted by aspring.
The head load pressure arm is lifted also.
FIGURE 2 - 5a) HEAD LOAD MECHANIS~l BASF 6106
FIGURE 2 - Sb) HEAD LOAD MECHANJSM BASF 6108
2 - 4
\

2.1.3 POSITIONING MECHAHIS~
The main parts of the positioning mechanism
are (see Fig. 2 - 4):
• Stepper
Motor
• Spiral Wheel
• Carriage Assembly
The stepper motor is a four phase motor and
1S rotated 150 by every step pulse.
The spiral wheel directly connected to the
shaft of the stepper motor converts the
rotational motion of the stepper motor to
a linear motion of the read write head
assenbly.
GUIDE BARS
R/W-HEAD
The BASF 6106 carriage assembly (Fig. 2 - 4a)
consists of the read/write head. and the head
load pressure
arm. The read/write head is inserted
in the carriage assembly, which rides on two guide
bars. The Flexy Disk is pressed against the readl
write head by the head load pressure arm. The head
load pressure
arm is released by the head load
mechanism.
In the BASF 6108 carriage assembly (Fig. 2 - 4b)
the head load pressure
pad is replaced by the upper
read/write head.
HEAD LOAD PRESSURE ARM
STEPPER MOTOR SHAFT
FIGURE 2 - 4 a) POSI rIONING MECHANISM BASF 6106
R/W-HEAO 0 (BUTTON TYPE)
R/W HEAD 1
(CA TAMARAN TYPE)
~~:jJ
FIGURE 2 - 4b) POSITIONING MECHANISM BASF 6108
2 - 3