MITSUBISHI ELECTRIC
5.25 INCH FLEXIBLE DISK DRIVES

MF501B 0.5 MB

MF503B 1.0 MB
MF504B 1.6 MB

SPECIFICATIONS and APPLICATION NOTES


The Mitsubishi MF500B range of double sided 5¼ inch flexible disk drives provide high performance and reliability giving a service life of over 20 000 hours.


This booklet gives guidance for applying the range of 5'/4 inch floppy drives. For more details consult the standard specification manual for each model.
Performance specifications


MF501B
MF503B
MF504B
Low density
MF504B
High Density
MFM recording



Unformatted capacity:-
Track
6.25KB
6.25KB
6.25KB
10.416KB
Disk
500KB
1000KB
1000KB
1666KB
Formatted
capacity:-





Sector
0.256KB
0.256KB
0.256KB
0.512KB
16 (15) sectors/
Track
Track
4.096KB
4.096KB
4.096KB
7.680KB
Disk
327.7KB
655.36KB
655.36KB
1228.8KB
Transfer rate

250kb/S
250Kb/s
250/300Kb/s
500Kb/s
Track density per inch
48 tpi
96 tpi
96 tpi
96 tpi
Total tracks

80
160
160
160
Access time





Track to track
6 mS
3 mS
3 mS
3 mS
Average
103 mS
94 mS
94 mS
94 mS
Settling time
15 mS
15 mS
15 mS
15 mS
Motor speed
300rpm
300rpm
300/360rpm
300rpm
Motor start time
250 mS
400 mS
400 mS
500 mS
Ready time
700 mS
700 mS
700 mS
700 mS

Environmental conditions
Operating
Storage
Transportation
Ambient temperature
5°C to 43 °C
-20°C to 60°C
-40°C to 60°C
Relative humidity
20% to 80%
10% to 90%
5% to 95%
Dimensions
Height 41mm
Width 146mm
Depth 195mm
Weight
1.2Kg



Reliability




MTBF
10 000 POH or more
MTTR
30 minutes
Unit life
5 years or 20 000 POH
Media life
3.5 million passes/track
Error rate
Soft error
10-9 bit


Hard error
10-12 bit



Seek error
10-6 bit



DC power connector
Pin number
Voltage
1
+12V DC
4 3 2 1
PCB
2
0V
3
0V
4
+5 VDC
DC power requirements + 5V ±5% 0.5A typ 0.7A
+12V ±5% 0.6A typ 1.0A max

A 0.25” frame ground connector is provided adjacent to the DC connector. The cut track option ‘FG’ isolates the DC OV from the frame ground.
Signal interface


Signal
I/O
Pin
0V


*
Spare
I/P
2
1
*
MF504B) This line switches between high and low density

In use
I/P
4
3


Drive select 3
I/P
6
5


Index
O/P
8
7
**
(MF501B) Standard ready or hold ready available

Drive select 0
I/P
10
9


Drive select 1
I/P
12
11


Drive select 2
I/P
14
13
**
(MF5038 & MF504B)
Standard ready, hold ready and disk-change available

Motor on
I/P
16
15


Direction select
I/P
18
17


Step
I/P
20
19



Write data
I/P
22
21

TTL levels


Write gate
I/P
24
23


Track 00
O/P
26
25
Low level (TRUE) OV to + 0.4V

Write protect
O/P
28
27
High level (FALSE) + 2.5V to + 5.25V

Read data
O/P
30
29
Input impedance 150 Ohms

Side one select
I/P
32
31
Receiver: SN7414N or equivalent
**
Ready
O/P
34
33
Driver: SN7438N or equivalent

Cabling and termination

Up to four drives may be connected by a ribbon cable in a daisy change configuration. A SIL terminator, supplied installed on the PCB, should be fitted to the last drive in the chain. On MF503B and MF5048 jumper ‘TD’ is installed to terminate drive select.

Power on sequence

No read/write operation may be performed until 100 mS after DC power is applied. The drive becomes ready after 600 mS (700mS for MF501B). The head must be stepped out to track 00 to provide a reference before track seeking begins.

Write precompensation

The drive uses high performance read/write heads with good compliance and media contact. This means that no write precompensation should be used. If write precompensation must be used, it should be 150 nS or less.
40 / 80 track switch option (MF503B)
The cut track option ‘ST’ may be cut to change to 40 track mode. A switch may be connected. An 80 track drive should not be used to write 40 track diskettes to be read by a 40 track drive. The PCB must not be damaged by track cuts or solder connections.
Option settings
Brackets around jumper name:– (MM) indicates jumper plug should be installed to select the function.
Jumper name
Function
(DS0)
DRIVE SELECT 0 enables the drive.
(DS1)
DRIVE SELECT 1 enables the drive. DS2 & DS3 etc.
(MX)
Drive is selected regardless of DRIVE SELECT lines
(MM) MS
Motor controlled by MOTOR ON signal
MM (MS)
Motor controlled by DRIVE SELECT signal
MM MS
Motor controlled by DRIVE SELECT AND MOTOR ON signal
(MM) (MS)
Motor controlled by IN USE signal latched by DRIVE SELECT signal. Option IU must be jumpered. (MF501B motor controlled by MOTOR ON signal)
(SR) DC HR DD
Standard READY sent on pin 34
(SR) DC (HR) DD
HOLD READY sent on pin 34 (MF503B, MF504B)
SR (DC) HR (DD)
DISK CHANGE (reset by DS) on pin 34 (MF5038, MF504B)
SR (DC) HR DD
DISK CHANGE (reset by step) on pin 34
SR DC
No ready signal sent
(RD)
Read data pulses inhibited by READY (MF504B)
(RI)
Index pulses gated by ready signal
(SS) SB
360 rpm when high density signal sent (MF504B)

300 rpm when low density signal sent (MF504B)
SS (SB)
360 rpm for high and low density (MF504)
(SS) SB (ND)
Low density 300 rpm set

LED lighting conditions (MF503B & MF504B)
MF501B LED is lit by IN USE OR DRIVE SELECT
(lU) (IS) (IL)
If IN USE is set, DRIVE SELECT latches LED on
(IU) ) IS (IL)
LED lit by sum of DRIVE SELECT above conditions
(IU) IS IL
LED lit by logical sum of DRIVE SELECT and IN USE.
(IV) (IS) IL
LED lit by IN USE signal
IU IS IL
LED lit by DRIVE SELECT signal
IU (IS) IL
LED will not light
(IR)
May be used with all the above. Requires that drive is ready before LED will light. Standard or Hold Ready must be selected if (IR) is used.

INPUT SIGNALS

Side one select
Logical ‘1’ selects head 0, logical ‘0’ selects head 1. A 100pS delay must be allowed after side select. After a write operation a 1mS delay (590pS for MF504B at high density) must be allowed before a side change or a track access. Direction select
Defines head stepping direction. Logical ‘1’ causes heads to step from the centre outward. Logical ‘0’ causes stepping inward.
Step
Pulses on this line move the head in the direction selected. The head steps one track on the trailing edge of a negative pulse (‘0’ to ‘1’).
Write gate
Logical ‘0’ enables data on the write line to be written on the selected side and track. Logical ‘1’ inhibits writing and enables reading. Data cannot be written if the write protect line is at ‘0’ because a write protected disk is present. Read data is output 1mS (590ps for MF504B at high density) after write gate becomes inactive.
Write data
Data written to the disk is sent on this line. The line is normally at ‘1’ and reverses the write current at the leading edge of a negative-going pulse (‘1’ to ‘0’). Writing is enabled by ‘0’ on the write gate.


Type
T1
T2
T3
T4
360rpm HD
150 to 1100ns
2.0µs ± 10ns
4.0µs ± 20ns
3.0µs ±15ns
360rpm LD
150 to 1800ns
3.33µs ± 17ns
6.7µs ± 33ns
5.0µs ±25ns
300rpm
150 to 2100ns
4.0µs ± 20ns
8.0µs ± 40ns
6.0µs ±30ns
For MF501B T1= 200 to 2100ns
In use
Logical ‘0’ lights the LED. (MF503B & MF504B have option jumpers for LED lighting conditions).
Motor on
Logical ‘0’ turns the motor on. The write gate does not go to ‘0’ until 500mS after the motor on line goes to ‘0’.
Normal density (MF504B only)
Logical ‘1’ selects high density read/write operation and logical ‘0’ selects normal density. With option jumpers SS shorted and SB open, this line changes the motor rpm and read/write 'operations are performed 400mS after density change, to allow the motor speed to stabilize. When motor rpm is switched the head must be moved to track 00 before reading or writing. With SB shorted and SS open the motor speed is always 360rpm so no waiting or track 00 seek is necessary.
OUTPUT SIGNALS
Index
A ‘0’ pulse of 3.5mS is output once for each revolution of the disk.

Track 00
Logical ‘0’ on this line indicates that the head is on track 00.
Ready
This line is at ‘1’ if the door is opened or the lever is up. A ‘0’ is produced when the DC power is applied, a diskette is properly clamped and 2 or more index pulses are detected. Option jumpers select the type of ready signal supplied.
Read data
This line outputs raw data (combined clock and data signals) converted into logical ‘0’ pulses.

Type
T1
T2
T3
T4
360rpm HD
2.0µs ± 400ns
4.0µs ± 800ns
3.0µs ± 600ns
300ns ± 150ns
360rpm LD
3.33µs ± 66ns
6.67µs ± 1333ns
6.0µs ± 1200ns
300ns ± 150ns
300rpm
4.0µs ± 800ns
8.0µs ± 16000ns
6.0µs ± 1000ns
300ns ± 150ns
For MF503B T4= 1.0µs ± 250ns
For MF501B T4= 0.8µs ± 250ns
HD – High density LD – Low density
Write protect
This signal goes to ‘0’ when a write protected disk is inserted into the drive. Writing is inhibited even if the write gate is active.

Control and data timing




Note 1
Wait 8ms before issuing a step pulse after changing direction.

Note 2
Applies to MF504B at high density.
Disk Drive and front bezel dimensions

Test points for alignment procedures


MF501B
MF503B
MF504B
Track 00 sensor
TPA 1
TPA 1
TPA 4
Read data output
TPA 3
TPA 3
TPA 3
Track 00 output
TPA 13
TPA 13
TPA 2
Index output
TPA 14
TPA 14
TPA 1
Differential
head output
TPB 9
TPB 10
TPB 9
TPB 10
TPB 5
TPB 6

Option jumper locations


Mitsubishi Electric (UK) Ltd., Hertford Place, Maple Cross, Rickmansworth Herts WD3 2BJ Tel 0923 770000 Tlx 296196 Fax 0923 777368