To operate the graphics card, this library uses a driver routine which must be compatible with your hardware. Fortunately, most modern hardware supports the VESA standard for SVGA modes. The GRX driver for VESA compatible cards is included in the SFS binary distribution. If your card does not support VESA modes, then you will need to get a different driver from the GRX distribution. To operate in a DOS box under Windows 3.1 or Windows 95, you need to use version 2 of the GRX library.
Replay is the most difficult thing to get right in an installation.
If you have had replay working once, then the most common cause of failure is that the DAC environment variable is not set. The 'replay' program should report an error if it can't determine the replay device. Surprisingly, a common problem. SFS needs to control DAC hardware on the machine the program is actually executing on. The complete set of settings for DAC may be found in the manual page for replay.