module1.bas

操作系统模拟,主要是文件系统和进调度

Attribute VB_Name = "Module"
Option Explicit
Public strFile As String
Public strName As String
Public bolEdit As Boolean
Type FCB    '文件控制块数据结构
    FileName As String * 3  '文件名
    FileType As String * 2  '扩展名
    Property As Byte        '目录、文件属性，1-目录、2-文件
    FirstBlock As Byte      '起始盘块号
    FileLen As Byte         '文件长度（目录为空）
End Type
Type PCB        '进程控制块数据结构
    OuterName As String         '外部标识符
    InnerName As Integer        '内部标识符
    
    PC As Integer               '程序计数寄存器(既地址指针)
    DR As Integer               '中间结果数据寄存器
    States As Integer           '进程状态 0-运行 1-就绪 2-阻塞
    PRI As Integer              '进程优先级
    Events As String            '事件，即阻塞原因
       
    Memp As Integer             '页表指针
    NextPCB As Integer          '链接指针
    WaitTime As Integer         '等待时间
End Type
Type DCT     '设备控制表数据结构
    Devname As String       '物理设备名
    DevLogname As String    '逻辑设备名
    bolDev As Boolean       '设备使用状态，ture-使用，false-空闲
    UseProc As Integer      '使用该设备的进程号
    WaitProc As Integer     '阻塞指针
End Type
Type Ram    '页表数据结构
    Pages() As Integer  '预定义0长度页表项（用于存放物理块号）
    MemLen As Integer   '所占内存长度
End Type
Type PSW    '防止中断向量丢失而设的缓冲
    Events(9) As String      'I/O中断号
    Number(9) As Integer     'I/O中断原因
    TimePSW As Integer      '时钟中断
    Rpointer As Integer     '读中断指针
    Wpointer As Integer     '写中断指针
End Type

Sub Main()
    Dim frmMainForm As frmMain
    Dim L As String
    
    
    Set frmMainForm = New frmMain
    Load frmMainForm
    
    frmMainForm.Show
  
    frmMainForm.txtRunPath.SetFocus
End Sub