Floppy Drive; Description; Drive Select Switch; Disk Format - Mitsubishi Electric LS Pro Hardware Technical Reference

4.4

FLOPPY DRIVE

Description

The floppy disk drive fitted in the LS Pro range is a 3.5", high density double-sided, one
inch high unit. The drive can read and write 3.5" discs with a formatted capacity of either
1.44Mbytes or 720 kbytes. The drive has a constant disk rotation speed of 300 rpm.
The different disk capacities are accommodated by different data transfer rates.
The 1.44 Mbyte media uses a data transfer rate of 500 kbits/sec. The 720 kbyte media
uses a data transfer rate of 250 kbits/sec.
Both types of media are double-sided with 80 tracks per side and a track density of 135
tracks per inch.
Drive select The drive select switch is set to identify the drive to the system. The switch is located
switch at the rear of the drive on the right-hand side. The switch is set to 0. The drive select
switch is shown below.

Disk format

1.44 Mbyte disks have a hole in the disk in the opposite corner to the write protect tab.
The drive uses this to determine the type of disk fitted. If the drive does not detect a
hole in the disk it treats it as a 720kbyte disk and changes the transfer rate to 250 kbits
per second.
The following details briefly describe the floppy disk formats for the two capacities of
disk.
720 kbytes disks
• double-sided
• 80 tracks/side
• 512 bytes/sector
• 9 sectors/track
1.44 Mbyte disks
• double-sided
• 80 tracks/side
• 512 bytes/sector
• 18 sectors/track
Peripheral items
LS PRO HARDWARE TECHNICAL REFERENCE 4/17
DRIVE SELECT
SWITCH