When IDE first became available some manufacturers put servo information in unprotected areas of the disk drive hence a low-level format would destroy this information. All Fujitsu disk drives write this data in a special area of the media which is impossible to access by the user. Fujitsu specify that as long as the low-level formatting utility sends only the FORMAT TRACK command as specified in the IBM PC-AT DIAGNOSTICS then no damage will occur. For drives other than of Fujitsu manufacture, read any accompanying documentation thoroughly before proceeding with a format.

My PC BIOS does not support the type 47 disk drive (user definable). What type should I use from the preset list for my drive?

Any Fujitsu ATA (IDE) drive is capable of emulating a suitable configuration automatically, so you should select the the largest drive your system BIOS table will permit without actually exceeding the total capacity of the drive. Please note when comparing the disk capacity that a megabyte is 1,000,000 bytes. If the capacity is not listed in the system BIOS table then you can also check suitablity by calculating the number of sectors available. This is the most accurate way of ascertaining suitability.

Sectors = [Sectors Per Track] x [Heads] x [Cylinders]

I've just acquired a 104MB drive and DOS and the system BIOS report the capacity as 99MB. Is the drive faulty?

No. MS-DOS and most BIOS' report a megabyte as being 1024 bytes × 1024 bytes. A megabyte is 1,000,000 bytes ( 1 × 10⁶ )

When I turn my computer on, I hear a rattling sound from the disk drive at various times when there should be no drive activity. What is this?

This is known as a thermal recalibration and is normal for the majority of modern hard disk drives. After the computer system has been turned on, as you can imagine, things begin to hot up a bit inside the cabinet. The disk drive, as it expands due to the temperature rise, must recalibrate itself to ensure that the heads are positioned directly over each track of the media. The rattling sound heard is the predefined routine taking place. The process takes approximately one second to complete. The most recent Fujitsu drives have the capability of interrupting this routine when a command is received from the host and resuming once the command is complete. The maximum time therefore that the host will ever wait for the drive to respond is 100 milliseconds.

I have set a Fujitsu SCSI drive at ID0 and the operating system reports that it is write protected.

Make sure that you have not inadvertently removed the write enable jumper from the drive. On most Fujitsu SCSI drives this jumper is located right next to the SCSI ID jumpers.

I thought SCSI was a standard. Why won't one SCSI controller read data written by another of different manufacture?

You are correct; SCSI is a standard but unfortunately SCSI does not come as standard on PCs. Each SCSI host adapter manufacturer has their own algorithm for translating the SCSI addressing method of Zero to the Total Number of Logical Data Blocks available on the drive to the system's requirement of a Head, Cylinder, Sector method of addressing. Until some conformity is arrived at then stick to the same controller when swapping drives about. When using magneto-optical disks try using either Super Floppy format or NSR format and this will cure your problems.

Where has the synchronous data transfer jumper gone from the new Fujitsu SCSI disk drives?

The jumper that was on most SCSI drives until the M268XSAM range was really surplus to requirements. It was a sadly misunderstood jumper in as much as it was thought that by disabling synchronous data transfer mode the speed of the drive would deteriorate. This is not so. Disabling the option only inhibited the drive from initiating any synchronous data transfers. If the host made a request of the drive to go synchronous then the response would be “How fast?” and then negotiation would begin.