3. Installation

Configuring Linux to support 3Dfx accelerators involves the following steps:

1. Installing the board.
2. Installing the Glide distribution.
3. Compiling, linking and/or running the application.

The next sections will cover each of these steps in detail.

3.1 Installing the board

Follow the manufacturer's instructions for installing the hardware or have your dealer perform the installation. It should not be necessary to select settings for IRQ, DMA channel, either Plug&Pray (tm) or factory defaults should work. The add-on boards described here are memory mapped devices and do not use IRQ's. The only kind of conflict to avoid is memory overlap with other devices.

As 3Dfx does not develop or sell any boards, do not contact them on any problems.

Troubleshooting the hardware installation

To check the installation and the memory mapping, do cat /proc/pci. The output should contain something like

  Bus  0, device  12, function  0:
    VGA compatible controller: S3 Inc. Vision 968 (rev 0).
      Medium devsel.  IRQ 11.  
      Non-prefetchable 32 bit memory at 0xf4000000.

  Bus  0, device   9, function  0:
    Multimedia video controller: Unknown vendor Unknown device (rev 2).
      Vendor id=121a. Device id=1.
      Fast devsel.  Fast back-to-back capable.  
      Prefetchable 32 bit memory at 0xfb000000.

With current kernels, you will probably get a boot warning like

Jun 12 12:31:52 hal kernel: Warning : Unknown PCI device (121a:1).
Please read include/linux/pci.h 

If you experience any problems with the board, you should try to verify that DOS and/or Win95 or NT support works. You will probably not receive any useful response from a board manufacturer on a bug report or request regarding Linux. Having dealt with the Diamond support e-mail system, I would not expect useful responses for other operating systems either.

Configuring the kernel

There is no kernel configuration necessary, as long as PCI support is enabled. The Linux Kernel HOWTO should be consulted for the details of building a kernel.

Configuring devices

The current drivers do not (yet) require any special devices. This is different from other driver developments (e.g. the sound drivers, where you will find a /dev/dsp and /dev/audio). The driver uses the /dev/mem device which should always be available. In consequence, you need to use setuid or root privileges to access the accelerator board.

3.2 Setting up the Displays

There are two possible setups with add-on boards. You could either pass-through the video signal from your regular VGA board via the accelerator board to the display, or you could use two displays at the same time. Rely to the manual provided by the board manufacturer for details. Both configurations have been tried with the Monster 3D board.

Single screen display solution

This configuration allows you to check basic operations of the accelerator board - if the video signal is not transmitted to the display, hardware failure is possible.

Beware that the video output signal might deteoriate significantly if passed through the video board. To a degree, this is inevitable. However, reviews have complained about below-average of the cables provided e.g. with the Monster 3D, and judging from the one I tested, this has not changed.

There are other pitfalls in single screen configurations. Switching from the VGA display mode to the accelerated display mode will change resolution and refresh rate as well, even if you are using 640x480 e.g. with X11, too. Moreover, if you are running X11, your application is responsible for demanding all keyboard and mouse events, or you might get stuck because of changed scope and exposure on the X11 display (that is effectively invisible when the accelerated mode is used) You could use SVGA console mode instead of X11.

If you are going to use a single screen configuration and switch modes often, remember that your monitor hardware might not enjoy this kind of use.

Single screen dual cable setup

Some high end monitors (e.g. the EIZO F-784-T) come with two connectors, one with 5 BNC connectors for RGB, HSync, VSync, the other e.g. a regular VGA or a 13W3 Sub-D VGA. These displays usually also feature a front panel input selector to safely switch from one to the other. It is thus possible to use e.g. a VGA-to-BNC cable with your high end 2D card, and a VGA-to-13W3 Sub-D cable with your 3Dfx, and effectively run dual screen on one display.

Dual screen display solution

The accelerator board does not need the VGA input signal. Instead of routing the common video output through the accelerator board, you could attach a second monitor to its output, and use both at the same time. This solution is more expensive, but gives best results, as your main display will still be hires and without the signal quality losses involved in a pass-through solution. In addition, you could use X11 and the accelerated full screen display in parallel, for development and debugging.

A common problem is that the accelerator board will not provide any video signal when not used. In consequence, each time the graphics application terminates, the hardware screensave/powersave might kick in depending on your monitors configuration. Again, your hardware might not enjoy being treated like this. You should use

setenv SST_DUALSCREEN 1

3.3 Installing the Glide distribution

The Glide driver and library are provided as a single compressed archive. Use tar and gzip to unpack, and follow the instructions in the README and INSTALL accompanying the distribution. Read the install script and run it. Installation puts everything in /usr/local/glide/include,lib,bin and sets the ld.conf to look there. Where it installs and setting ld.conf are independent actions. If you skip the ld.conf step then you need the LD_LIBRARY_PATH.

You will need to install the header files in a location available at compile time, if you want to compile your own graphics applications. If you do not want to use the installation as above (i.e. you insist on a different location), make sure that any application could access the shared libary at runtime, or you will get a response like can't load library 'libglide.so'.

Using the detect program

There is a bin/detect program in the distribution (the source is not available). You have to run it as root, and you will get something like

slot  vendorId   devId   baseAddr0  command  description
----  --------  ------  ----------  -------  -----------
  00    0x8086  0x122d  0x00000000   0x0006  Intel:430FX (Triton)
  07    0x8086  0x122e  0x00000000   0x0007  Intel:ISA bridge
  09    0x121a  0x0001  0xfb000008   0x0002  3Dfx:video multimedia adapter
  10    0x1000  0x0001  0x0000e401   0x0007  ???:SCSI bus controller
  11    0x9004  0x8178  0x0000e001   0x0017  Adaptec:SCSI bus controller
  12    0x5333  0x88f0  0xf4000000   0x0083  S3:VGA-compatible display co

Permission denied: Failed to change I/O privilege. Are you root?

Using the test programs

Within the Glide distribution, you will find a folder with test programs. Note that these test programs are under 3Dfx copyright, and are legally available for use only if you have purchased a board with a 3Dfx chipset. See the LICENSE file in the distribution, or their web site www.3dfx.com for details.

It is recommend to compile and link the test programs even if there happen to be binaries in the distribution. Note that some of the programs will requires some files like alpha.3df from the distribution to be available in the same folder. All test programs use the 640x480 screen resolution. Some will request a veriety of single character inputs, others will just state Press A Key To Begin Test. Beware of loss of input scope if running X11 on the same screen at the same time.

See the README.test for a list of programs, and other details.