ASPI Setup Instructions

1. Introduction

WinDAC32 works best if an ASPI (Advanced SCSI Programming Interface) manager is installed (under Windows 9X it is required). Now you may think: "I'm using only ATAPI devices, why do I have to use a SCSI Programming Interface?". The answer is simple: Windows 9X and NT internally operate only with SCSI devices and all devices have to be accessed through a SCSI miniport driver, even if they are not SCSI devices. So, the miniport drivers are responsible for converting the commands sent by Windows to the drive in the format expected by the drive. ATAPI devices use almost the same command set as specified in the SCSI Specification with the only exception being the communication protocol.

2. Installation of the ASPI Manager

Since this differs depending on the Windows version used, I will describe them in the following sections.

2.1 Windows 9X

Normally, there is no need to install an ASPI manager for Windows 9X because it installs its own (an old version from Adaptec). The default ASPI manager works fine with SCSI and ATAPI drives and should be enough for most purposes. But sometimes you may wish to install an updated version of an ASPI Manager because you have found some problems or bugs (I found only one bug and it doesn't seem to cause any problems). In this case, you can look for a newer version. The only company offering ASPI drivers for Win9X seems to be Adaptec, so have a look at their homepage for updates. These updates won't install without an installed Adaptec host adapter or Adaptec software, but you can simply install a Windows driver for a non PnP SCSI Controller like the 1505 included in Win9x and activate it, even you don't have such an adapter. After that you should be able to install the update. I am not sure if or how this will work in Windows 98.

2.2 Windows NT

Unfortunately, Microsoft does not supply an ASPI Manager with Windows NT up to version 4.0 (not even with the service packs or in the current Windows 2000 beta version). You will have to find an ASPI Manager for NT. For NT, Adaptec is not the only company offering an ASPI Manager, Symbios Logic or Mylex have their own versions (I'm not sure about the Mylex one, as it is only a DLL without a system driver). The Adaptec CD-Writing programs are installing a current version of their ASPI Manager.

3. ASPI Setup

If WinDAC32 could not detect an ATAPI device, (when the program is first launched, or after executing the rescan drives command, or if you have updated or installed an ASPI Manager) you have to change the configuration of the ASPI Manager.
In the case that WinDAC32 couldn't load the ASPI Manager under Win9X after these changes, it is possible that the CDROM drives are operating in the DOS compability mode (drivers for these devices are loaded in the Config.sys or Autoexec.bat).

3.1 Windows 9X

Here you have two options to make the ASPI Manager work with ATAPI devices again.
The first option is to downgrade to the original Win9X ASPI Manager by extracting and copying the following files from the Win9X CAB files to the directories:

WNASPI32.DLL -> WIN\SYSTEM
WINASPI.DLl  -> WIN\SYSTEM
APIX.VXD     -> WIN\SYSTEM\IOSUBSYS
ASPI2HLP.SYS -> WIN

The second option is much more simple. Open the registry editor (regedit) and open the key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\APIX

If it doesn't exist, create it and after that create the following entry:

ExcludeMiniports=""

You can also use the following Reg file to do this, simply download it and double click on it.

3.2 Windows NT

Since there is no default ASPI Manager, you can't downgrade to an older version like in Win95. But even here it is possible to change the setup by adding this entry to the registry.

Open the registry editor (regedit) in Windows NT and open the key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ASPI32\Parameters

If it doesn't exist, create it and after that create the following entry:

ExcludeMiniports=""

You can also use the following Reg file to do this, simply download it and double click on it.