floppyformat.java

JPC: x86 PC Hardware Emulator. 牛津大学开发的一个纯JAVA的x86系统结构硬件模拟器。

/*
    JPC: A x86 PC Hardware Emulator for a pure Java Virtual Machine
    Release Version 2.0

    A project from the Physics Dept, The University of Oxford

    Copyright (C) 2007 Isis Innovation Limited

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License version 2 as published by
    the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
    Details (including contact information) can be found at: 

    www.physics.ox.ac.uk/jpc
*/

package org.jpc.emulator.peripheral;

public class FloppyFormat
{
    private static final int DISK_288   = 0x01; // 2.88 MB disk
    private static final int DISK_144   = 0x02; // 1.44 MB disk
    private static final int DISK_720   = 0x03; // 720 kB disk
    private static final int DISK_USER  = 0x04; // User defined geometry
    private static final int DISK_NONE  = 0x05; // No disk

    private static final FloppyFormat[] formats = {
	/* First entry is default format */
	/* 1.44 MB 3"1/2 floppy disks */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 18, 80, 1, "1.44 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 20, 80, 1,  "1.6 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 21, 80, 1, "1.68 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 21, 82, 1, "1.72 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 21, 83, 1, "1.74 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 22, 80, 1, "1.76 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 23, 80, 1, "1.84 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_144, 24, 80, 1, "1.92 MB 3\"1/2" ),
	/* 2.88 MB 3"1/2 floppy disks */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_288, DISK_288, 36, 80, 1, "2.88 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_288, DISK_288, 39, 80, 1, "3.12 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_288, DISK_288, 40, 80, 1,  "3.2 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_288, DISK_288, 44, 80, 1, "3.52 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_288, DISK_288, 48, 80, 1, "3.84 MB 3\"1/2" ),
	/* 720 kB 3"1/2 floppy disks */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_720, 9, 80, 1,  "720 kB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_720, 10, 80, 1,  "800 kB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_720, 10, 82, 1,  "820 kB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_720, 10, 83, 1,  "830 kB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_720, 13, 80, 1, "1.04 MB 3\"1/2" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_720, 14, 80, 1, "1.12 MB 3\"1/2" ),
	/* 1.2 MB 5"1/4 floppy disks */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 15, 80, 1,  "1.2 kB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 18, 80, 1, "1.44 MB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 18, 82, 1, "1.48 MB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 18, 83, 1, "1.49 MB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 20, 80, 1,  "1.6 MB 5\"1/4" ),
	/* 720 kB 5"1/4 floppy disks */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 9, 80, 1,  "720 kB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 11, 80, 1,  "880 kB 5\"1/4" ),
	/* 360 kB 5"1/4 floppy disks */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 9, 40, 1,  "360 kB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 9, 40, 0,  "180 kB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 10, 41, 1,  "410 kB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 10, 42, 1,  "420 kB 5\"1/4" ),
	/* 320 kB 5"1/4 floppy disks */ 
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 8, 40, 1,  "320 kB 5\"1/4" ),
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_120, DISK_288, 8, 40, 0,  "160 kB 5\"1/4" ),
	/* 360 kB must match 5"1/4 better than 3"1/2... */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_144, DISK_720, 9, 80, 0,  "360 kB 3\"1/2" ),
	/* end */
	new FloppyFormat( FloppyController.FloppyDrive.DRIVE_NONE, DISK_NONE, -1, -1, 0, "" )
    };
    
    private int drive;
    private int disk;
    private int lastSector;
    private int maxTrack;
    private int maxHead;
    private String description;
    
    private FloppyFormat(int drive, int disk, int lastSector, int maxTrack, int maxHead, String description)
    {
	this.drive = drive;
	this.disk = disk;
	this.lastSector = lastSector;
	this.maxTrack = maxTrack;
	this.maxHead = maxHead;
	this.description = description;
    }

    public int heads()
    {
	return maxHead + 1;
    }

    public int tracks()
    {
	return maxTrack;
    }

    public int sectors()
    {
	return lastSector;
    }

    public int drive()
    {
	return drive;
    }

    public long length()
    {
	return heads() * tracks() * sectors() * 512;
    }

    public String toString()
    {
	return description;
    }

    public static FloppyFormat findFormat(long size, int drive)
    {
	int firstMatch = -1;
	for (int i = 0; i < formats.length; i++) {
	    if (formats[i].drive() == FloppyController.FloppyDrive.DRIVE_NONE)
		break;
	    if ((drive == formats[i].drive()) || (drive == FloppyController.FloppyDrive.DRIVE_NONE)) {
		if (formats[i].length() == size) {
		    return formats[i];
		}
		if (firstMatch == -1)
		    firstMatch = i;
		
	    }
	}
	if (firstMatch == -1)
	    return formats[1]; // Should this return the NULL format?
	else
	    return formats[firstMatch];
    }
}