Hej August!

 AA> The problem was that my usb drives needed to be FAT formated.  My
 AA> media player (which is about 10 yrs old now) only supports usb
 AA> drives that are FAT formatted.

I've run across this issue many, many times.  It makes me happy that I never bought one of those when they were all the rage.  These days I am more likely to run into people having issues with playing mpegs and the such that are incompatible with Apple media software.  I have yet to run across one of them that has issues with FAT formatted usb disks.

The more I run across these types of issues, the more I pat myself on the back with sticking with Linux all this time.  I seriously doubt I could just pick it up nowadays as it took me decades to reach where I am now.  Learning all this now would be impossible for me.

I can appreciate your want for a suitable split.  The busybox one looks to be the winner in your situation although a properly modern gnu one would have been the best of all, were it a reality.

  :read !file /usr/bin/split
/usr/bin/split: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 4.19.0, stripped

Gotta love it.  :-)

Het leven is goed,
Maurice

-o   -o   -o    o-   o-  -o    o-  -o    o-  -o   -o    o-   o-  -o   -o    o-
 (\   (\   (\  /)   /)    (\  /)    (\  /)    (\   (\  /)   /)    (\   (\  /)
 ^^   ^^   ^^  ^^   ^^    ^^  ^^    ^^  ^^    ^^   ^^  ^^   ^^    ^^   ^^  ^^
... Lieve zestien pingu‹ns van de Apocalyps.
--- GNU bash, version 5.2.32(1)-release (x86_64-pc-linux-gnu)