                           TVicHw32 version 1.1

                   Copyright (C) 1997 Victor Ishikeev
              Portions Copyright (C) 1997 EnTech Taiwan
                     e-mail: tools@entechtaiwan.com

                                 README



CONTENTS
========

1. OVERVIEW
2. REGISTRATION
3. INSTALLATION
4. GENERAL TVicHW32 COMPONENT PROPERTIES AND METHODS
5. DIRECT MEMORY ACCESS WITH TVicHW32
6. DIRECT PORT I/O WITH TVicHW32
7. HARDWARE INTERRUPT HANDLING WITH TVicHW32
8. CONTACT INFORMATION


1. OVERVIEW
===========

TVicHW32 is a shareware component for use with Delphi 2.0 which 
allows you to control hardware from a Win32 application without using
the Windows DDK. TVicHW32 provides transparent support for Windows 95
and Windows NT, providing Delphi programmers with a standard method 
for real-time direct access to port I/O, memory I/O, and hardware 
interrupts - without requiring you to write a custom virtual device
driver for Windows 95 or a kernel-mode driver for NT.

Evaluation copies of the TVicHW32 component consist of the following
elements:

  - vichw00.vxd and vichw00.sys
    evaluation run-time kernel mode drivers, which manage all port
    and memory I/0, and interrupt handling
  - hw_32.dcu and loadhw.dcu
    Delphi interface units to the kernel mode drivers
  - hw_test.dpr and main.*
    Sample program, with source, demonstrating some of the features
    of the TVicHW32 component

2. REGISTRATION
===============

TVicHW32 is shareware. You must read and accept the terms detailed in
the license.txt file before you can use this component. An order form
is provided in the file order.txt for the purpose of registering this 
component.

Registered users will receive:

  - vichw11.vxd and vichw11.sys
    royalty-free run-time kernel mode drivers, which manage all port
    and memory I/0, and interrupt handling
  - hw_32.pas and loadhw.pas
    Delphi interface source code to the kernel mode drivers

TVicHW32 is maintained at the following internet address:
  http://www.entechtaiwan.com/tools.htm
  e-mail: tools@entechtaiwan.com

where you can find the latest release and links to support and on-line
ordering sites.

3. INSTALLATION
===============

TVicHW32 is installed on the "Drivers" page of the VCL palette, by 
following the steps below:

  1) Create a directory for the TVicHW32 component, e.g., C:\HW
  2) For use with Windows 95, copy the vichwXX.vxd file to your 
     Windows 95 system directory, e.g., C:\WINDOWS\SYSTEM
  3) For use with Windows NT, copy the vichwXX.sys file to your
     Windows NT drivers directory, e.g., C:\WINDOWS\SYSTEM32\DRIVERS
  4) Add the TVicHW32 component to your Delphi component library by
     selecting Component|Install|Add... and then click Ok to rebuild
     the library

4. GENERAL TVicHW32 COMPONENT PROPERTIES AND METHODS
====================================================

After successfully adding the TVicHW32 component to your VCL, and
after copying the kernel-mode driver(s) to the appropriate Windows
directories, you can test the functionality of the component, and 
examine the sample code provided, by opening the included HW_TEST 
demonstration program.

TVicHW32 has the following general component properties and methods:

    constructor Create (Owner: TComponent); override;
    -------------------------------------------------
    The Create method allocates memory to create the TVicHW32 
    component and initializes data as needed. Note that Create does 
    *not* automatically open the kernel-mode driver: you must open the
    kernel-mode driver with the OpenDriver method (see below).

    You do not normally need to directly call the Create method; the 
    component is automatically created at run-time.
    
    destructor Destroy; override;
    -----------------------------
    The Destroy method destroys the TVicHW32 component releases the 
    memory allocated to it. If a hardware interrupt was "unmasked" to
    permit direct access, the "mask" is automatically restored, and if 
    the kernel-mode driver was opened, it is automatically closed.

    You do not normally need to directly call the Destroy method; the 
    component is automatically destroyed when the application closes.

    procedure OpenDriver;
    ---------------------
    Loads the vichwXX.vxd (under Windows 95) or vichwXX.sys (under 
    Windows NT) kernel-mode driver, providing direct access to the 
    hardware. If the kernel-mode driver was successfully opened, the
    boolean ActiveHW property (see below) will be set to True; if the 
    procedure fails, the ActiveHW property will be False.

    procedure CloseDriver;
    ----------------------
    Closes the kernel-mode driver and releases memory allocated to it.
    If a hardware interrupt was "unmasked", the "mask" is restored. If the
    driver was successfully closed, the ActiveHW property (see below) will
    be set to False.

    property ActiveHW: Boolean; (published, read);
    ----------------------------------------------
    The read-only and run-time ActiveHW property specifies whether the
    kernel-mode driver is open. ActiveHW returns True if the driver is
    open, or False if it is not.


5. DIRECT MEMORY ACCESS WITH TVicHW32
=====================================

The following function permits direct memory acccess:

    function MapPhysToLinear (PhAddr: dWord; Size: dWord): Pointer;
    ---------------------------------------- ----------------------
    Maps a specific physical address to a pointer in linear memory, 
    where PhAddr is the base address and Size is the actual number of
    bytes to which access is required.

    Note that a subsequent call to MapPhysToLinear invalidates the 
    previous pointer.

    The following example returns a pointer to the system ROM BIOS area:

    type 
      TBiosArray = array [0 ..255] of Byte;
      PBiosArray = ^TBiosArray;

    var 
      pBIOS: PBiosArray;

    begin
      with VicHw32 do
      begin
        OpenDriver;
        if ActiveHW then
        begin
          PBIOS:=MapPhysToLinear ($F8000,256)   // 255 bytes beginning at $F8000
          {...working with pBIOS...}
          CloseDriver;
        end
        else ShowMessage('ERROR: Kernel-mode driver is not open.'); 
      end;
    end;

6. DIRECT PORT I/O WITH TVicHW32
================================

For access to the 80x86 CPU data ports, TVicHW32 provides an implementation of
the traditional Borland Pascal 7 predefined arrays, Port and PortW, and adds PortL 
(which accepts a DWORD) and a "Hard/Soft" boolean switch. 

When a value is assigned to an array of type Port, PortW, or PortL, the value is output
to the selected port. When an array of type Port, PortW or PortL is referenced in an 
expression, its value is input from the selected port. Use of the Port, PortW and PortL
arrays are restricted to assignment and reference in expressions only.

The following properties permit direct I/O port access:

    property Port[Index: Word]: Byte; (public, read, write);
    --------------------------------------------------------
    Value of the Port array is of type Byte.

    property PortW [Index: Word]: Word; (public, read, write);
    --------------------------------------- ------------------
    Value of the PortW array is of type Word.

    property PortL [Index: Word]: dWord; (public, read, write);
    --------------------------------------- -------------------
    Value of the PortL array is of type DWord.

    property HardAccess: Boolean; (published, read, write);     
    --------------------------------------- ---------------
    The HardAccess property determines whether the kernel-mode driver
    should use "hard" or "soft" access to the I/O ports. If set to True
    "hard" access is employed; if set to False "soft" access is employed.

    "Soft" access provides higher performance access to ports, but may fail
    if the port(s) addressed are already in use by another kernel-mode 
    driver. While slower, "Hard" access provides more reliable access to
    ports which have already been opened by another kernel-mode driver. 

    The following example demonstrates direct port I/O calls, and generally
    complies with traditional Borland Pascal 7 syntax to facilitate porting
    16-bit code to Delphi 2:

    with VicHw32 do
    begin
      {...}
      Port[$2F8]:=$34;     // write a byte to port
      {...}
      MyByte:=Port[$2f9];  // read a byte from a port
      {...}
    end;


7. HARDWARE INTERRUPT HANDLING WITH TVicHW32
============================================

In a Win32 environment, hardware interrupts are normally hidden or "masked" 
by Windows; the TVicHW32 kernel-mode driver allows you to "unmask" the interrupt 
for direct handling by your application. Note that only one interrupt can be 
handled at a time.

The following properties and methods permit access to hardware interrupts.

    property OnHwInterrupt: TNotifyEvent; published;
    ------------------------------------------------
    Notification event that a specific hardware interrupt has occurred. 

    property IRQNumber: Byte; (published, read, write)
    --------------------------------------------------
    Specifies which hardware interrupt (IRQ1..15) is to be unmasked for 
    processing. Note that IRQ0 (the system timer) is *not* supported.

    procedure SetIRQ;
    -----------------
    Assign the interrupt specified by the IRQNumber property to the 
    OnHwInterrrupt event, and sets the IsIRQSet property (see below) to True.

    procedure UnmaskInterrupt;
    --------------------------
    Unmasks the hardware interrupt specified by the IRQNumber property, so that
    an OnHWInterrupt event will be generated when a hardware interrupt occurs,
    and sets the Masked property (see below) to False. 

    procedure MaskInterrupt;
    ------------------------
    Masks the hardware interrupt specified by the IRQNumber property.

    procedure DestroyIRQ;
    ---------------------
    Frees the memory and code previously assigned for unmasking the hardware
    interrupt specified by the IRQNumber property, setting the IsIRQSet property
    to False and the Masked property to True.

    property IsIRQSet: Boolean; (read only);
    ----------------------------------------
    Read-only property which specifies whether the hardware interrupt handler has
    been created by the SetIRQ method.
 
    property Masked: Boolean; (read only);
    --------------------------------------
    Read-only property which specifies whether the hardware interrupt handler has
    been removed (True), or is still active (False).

    property IRQCounter: dWord; (read only);
    ----------------------------------------
    Read-only property which counts the number of hardware interrupts intercepted
    by the TVicHW32 kernel-mode driver. The IRQCounter property is provided largely
    for debugging purposes, allowing you to compare the actual number of hardware
    interrupts generated with the number processed by your application.
    
    procedure SimulateHwInt;
    ------------------------
    This procedure is provided for purposes of debugging, and allows you to 
    simulate a hardware interrupt. When this procedure is called, the TVicHW32 
    kernel-mode driver will feign a "hardware interrupt", without directly affecting
    the hardware.

8. CONTACT INFORMATION
======================

Comments, questions and suggestions regarding TVicHW32 can be directed by e-mail to
victor@ivi.ugatu.ac.ru or tools@entechtaiwan.com. 

With best wishes,

Victor Ishikeev
March 1997
