Qspy is a cool program that allows you to find servers, their ping times and jump right into playing Quake -- it is highly recommended.
To get it operating with the Assassin 3D, just change the command line from Q95.BAT to Q95A.BAT click here to download Q95A.BAT.
This change is made within Qspy. Click on the View menu and select Options... Then, click on the Gameplay and change the 'Quake command line' to Q95A.BAT. Click Here to see a screen shot of the Qspy Gameplay setup screen.
No extra changes need to be made to support QuakeWorld, GLQuake or WinQuakey