Changes

Disk drives

2,032 bytes added, 10:53, 16 June 2011
/* Amstrad parts numbers */
 
== Technical Information ==
 
Characteristics of a disc drive:
 
* Number of sides
* Number of tracks
* Rotational speed
* Ready signal
* Density of the media it can read
* Disc format
* Capacity
 
=== Number of Sides ===
 
Number of sides is 1 (single sided) or 2 (double sided).
 
AMSDOS is designed for single sided drives. This means it will only read 1 side of a double sided disc.
To use both sides of a double sided disc you need another DOS (ParaDOS, ROMDOS etc).
 
The number of sides determines the total capacity that this drive can access.
 
===Number of Tracks ===
 
Number of tracks is either 40 or 80.
 
The number of tracks determine the total capacity that this drive can access.
 
NOTE: It is possible to read a disc created on a 40 track drive in an 80 track drive.
 
=== Rotational Speed ===
 
The rotational speed is either 300rpm or 360rpm, and it is the speed at which the disc is rotated within the drive when the motor is active.
The speed of the motor doesn't affect data transfer rate.
 
=== Ready signal ===
 
The CPC floppy disc controller requires a "ready" signal from the drive.
 
The drive is ready when:
* the disc motor is on,
* the drive is selected
* a disc is in the drive
* the rotational speed has stabalised (a short time after motor is switched on)
 
=== Density of the media it can read ===
 
The drive is designed for one or more specific media densities which it can read.
 
Low density (FM), Double Density (MFM), High Density (MFM).
 
Examples of low-density:
 
* BBC Micro DFS formatted discs.
 
Examples of double density:
 
* 360K 5.25" PC MS-DOS formatted discs
* 720K 3.5" PC MS-DOS formatted discs
 
Examples of high density:
 
* 1.2MB 5.25" PC MS-DOS formatted discs
* 1.44MB 3.5" PC MS-DOS formatted discs
The Amstrad disc controller can only read Double density discs.
 
The density of the media determines the total capacity of the drive.
 
=== Capacity ===
 
This defines the total capacity or capability of the drive. The actual useable amount depends on the filesystem that is written to it.
==Amstrad parts numbers==
2,541
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