The HARDWARE 1 course IT YBET

As of the first PC, the floppy drive was installed. Indeed, the first XT did not comprise hard disks.

A floppy disk drive is made up:

• a rotation motor which enters in action only at the time of the access
• 1 or 2 read/write heads
• 1 element of translation of the heads
• the electronics for control.

One finds two formats of readers and 5 capacities (formatted) according to the format.

5"1/4300K (simple face, simple density)

1,2 MB (double face, double density)

3"1/2 720 K (double face)

1,44 MB (double face, high density) (called HD)

2,88 MB (disappeared special diskettes)

One can install two disk drives on only one controller (and only one controller). The readers are connected to the controller by a cable 34 wire. At the end of the cable, two wire are reversed. Reader called a: puts itself at the end, the reader B (second reader) in the central connector. This can nevertheless be reversed in the BIOS. Two types of connectors are generally established with each connections, for a reader 3"1/2 and for a reader 5"1/4. The use of the readers 5"1/4 disappeared since first 486.

Somme ZIP 100 MB of Iomega of the first generation use the controller of diskette. Moreover, the first tape readers (backup, safeguard) also used this controller. Currently, Zip are connected on the hard disk controller IDE (possibly SCSI). The bands use either a controller owner, or an interface SCSI, the latter being reserved for the safeguard network (on server) with the sights of the capacities of these bands (several tens of GB) for speed and as controller SCSI is already established at the beginning...

The floppy disks must also be announced in the setup PC (according to the type and the capacity). Attention that 486 and the lower uses a reader 5"1/4 in a: by defect.

A remark for the data-processing technicians, please protect all the diskettes that you use as customers against writing. This avoids the virus propagation.

IT course 1: computer and peripherals. IT course 2: network, server and communication

Competences with the service of quality in data-processing