finalvar.java

这是由Java编写的小型模拟操作系统

final class FinalVar
{
	//CPU的工作状态，0为核心态，1为用户态
	public static final byte CPUMODE_USER = 1;
	public static final byte CPUMODE_SYS = 0;
	
	//CPU的C条件寄存器
	public static final char CPUC_T = 'T';
	public static final char CPU_F = 'F';
	
	//通道寄存器状态，1为忙，0为空闲
	public static final byte CHST_STAT_BUSY = 1;
	public static final byte CHST_STAT_FREE = 0;
	
	//内存容量
	public static final int MM_MAX_CAP = 1200;
	
	//内存总页数
	public static final int MM_PAGE_MAXCAP = 30;
	
	//内存单位状态，1为已分配，0为未分配
	public static final byte MM_MALLOCED = 1;
	public static final byte MM_FREE = 0;
	
	//内存读模式,1为读一行,2为读一页
	public static final byte MM_READ_WORD = 1;
	public static final byte MM_READ_PAGE = 2;
	
	//磁盘容量
	public static final int DISK_MAX_CAP = 4000;
	
	//磁盘总页数
	public static final int DISK_PAGE_MAXCAP = 100;
	
	//磁盘单位状态，1为已分配，0为未分配
	public static final byte DISK_MALLOCED = 1;
	public static final byte DISK_FREE = 0;
	
	//键盘缓冲区起始地址
	public static final byte KB_BUFFER_ADDR = 29;
	
	//键盘缓冲区大小
	public static final byte KB_BUFFER_SIZE = 1;
	
	//打印机缓冲区起始地址
	public static final byte PRT_BUFFER_ADDR = 25;
	
	//打印机缓冲区大小
	public static final byte PRT_BUFFER_SIZE = 4;
	
	//输入井起始地址
	public static final byte IN_BUFFER_ADDR = 0;
	
	//输出井起始地址
	public static final byte OUT_BUFFER_ADDR = 90;
	
	//输入井和输出井大小
	public static final byte SPOOLING_BUFFER_SIZE = 10;
	
	//进程状态，1为运行，2为就绪，3为阻塞
	public static final byte PCB_RUN = 1;
	public static final byte PCB_READY = 2;
	public static final byte PCB_BLOCK = 3;
	
//	刚刚添加；
//	作业状态，未被调度(-1)；
	public static final byte JCB_NOT_START = -1;

// 刚刚添加;
//	启动通道2的工作方式，1为表示从键盘缓存区读到输入井或从内存程序区读到输出井，0表示表示从输入井读到内存程序区或从输出井读到打印缓存区；
	public static final byte CHST3_READ = 1;
	public static final byte CHST3_WRITE = 0;
}