I've been sharing info about FreeDOS on Both.org
Here's one about how to edit the system config file:
The main configuration file for FreeDOS is a file in the root directory called FDCONFIG.SYS. This file contains a series of lines, each setting a value such as LASTDRIVE=Z or FILES=40
“Customize your FreeDOS with FDCONFIG.SYS”
—Learn how to configure FreeDOS with FDCONFIG.SYS


