How to install FreeDos onto a usb stick?

Unfortunately the current information on the FreeDOS Wiki is not up to date, but with the help from FreeDos Developer Jim Hall I could find the solution:

1. Download the USB “Full” installer from the FreeDOS page.
2. Unpack the downloaded zip
3. Use a USB formatting tool (for example rufus) to write the image to USB (take care to write over the right drive)
4. Move the directory D:\FDSETUP\BIN to D:\BIN

5. Edit first and last two lines in D:\FDCONFIG.SYS as follows

   !COUNTRY=001,858:\BIN\COUNTRY.SYS
   !LASTDRIVE=Z
   !BUFFERS=20
   !FILES=40
   
   DOS=HIGH
   DOS=UMB
   DOSDATA=UMB
   
   DEVICE=\BIN\HIMEMX.EXE
   
   SHELLHIGH=COMMAND.COM \BIN /E:2048 /P=\AUTOEXEC.BAT
   

6. Edit D:\AUTOEXEC.BAT as follows (Windows will hide this file, but you can open it by directly giving the filename). Only the line setting the DOSDIR needs to be changed and some display code at the end of AUTOEXEC.BAT are to be removed

   @echo off
   SET DOSDIR=
   SET LANG=
   SET PATH=%dosdir%\BIN
   
   SET DIRCMD=/P /OGN /Y
   
   rem SET TEMP=%dosdir%\TEMP
   rem SET TMP=%TEMP%
   
   rem SET NLSPATH=%dosdir%\NLS
   rem SET HELPPATH=%dosdir%\HELP
   rem SET BLASTER=A220 I5 D1 H5 P330
   rem SET COPYCMD=/-Y
   
   DEVLOAD /H /Q %dosdir%\BIN\UDVD2.SYS /D:FDCD0001
   
   SHSUCDX /QQ /D3
   
   rem SHSUCDHD /QQ /F:FDBOOTCD.ISO
   
   FDAPM APMDOS
   
   rem SHARE
   
   rem NLSFUNC %dosdir%\BIN\COUNTRY.SYS
   rem DISPLAY CON=(EGA),858,2)
   rem MODE CON CP PREP=((858) %dosdir%\CPI\EGA.CPX)
   rem KEYB US,858,%dosdir%\bin\keyboard.sys
   rem CHCP 858
   rem PCNTPK INT=0x60
   rem DHCP
   rem MOUSE
   
   rem DEVLOAD /H /Q %dosdir%\BIN\UIDE.SYS /H /D:FDCD0001 /S5
   
   SHSUCDX /QQ /~ /D:?SHSU-CDR,D /D:?SHSU-CDH,D /D:?FDCD0001,D /D:?FDCD0002,D /D:?FDCD0003,D
   
   rem MEM /C /N
   
   SHSUCDX /D
   
   rem DOSLFN
   
   rem LBACACHE.COM buf 20 flop
   
   SET AUTOFILE=%0
   SET CFGFILE=\FDCONFIG.SYS
   alias reboot=fdapm warmboot
   alias reset=fdisk /reboot
   alias halt=fdapm poweroff
   alias shutdown=fdapm poweroff
   
   rem alias cfg=edit %cfgfile%
   rem alias auto=edit %0
   
   vecho /p Done processing startup files /fCyan FDCONFIG.SYS /a7 and /fCyan AUTOEXEC.BAT /a7/p
   

7. Delete D:\SETUP.BAT

8. Done, safe your files and safely remove the USB stick

Boot and test

The USB key now boots directly into FreeDOS and loads into high memory, leaving roughly 600KB of common memory for programs.