Hi,
there was a long thread here on SNA23-33 repair.
Zebra stripes on the display and such.
Drive A: and B: are both the floppy drive, with mechanical
swapping. C is the flash board, can be changed only
with a special bootable service disk.
There are 2 batteries: The usual Dallas clock chip with built-in
battery that was common in old PCs and an orange Renata
lithium battery.
<
https://www.eevblog.com/forum/repair/wg-sna-2023-spectrum-analyzer-repair/50/ >
The service disk is probably from the old thread.
The dd_from.... file is a image file made with the Linux command dd ( = disk dump ).