mmm in amigamerlin drivers the refresh for glide doesn't work because u have to put this in your registry.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3dfxvs\Device0\Glide]
"FX_GLIDE_USE_APP_REFRESH"="1"
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3dfxvs\Device0\Glide]
"FX_GLIDE_USE_APP_REFRESH"="1"