The $OEM$\Textmode directory contains all of the files that the Setup Loader needs to load, and that Text Mode Setup needs to copy to the target computer, so that the system can boot into GUI setup.
If you are installing SCSI, keyboard, video, or pointer device drivers, or HALs, that are not included with the Windows NT Workstation 4.0 retail version, this directory should also contain a standard Txtsetup.oem file. This file contains pointers to all the files required by the Setup Loader and Text Mode Setup to load and install these componentsTMTM. On x86 machines, Txtsetup.oem and all files listed in it (HALs and drivers), must also be listed in the [OEMBootFiles] section of the answer file.