DaveDDS wrote on 2025-07-31, 09:59:

Curious - what are you referring to by "online decompiler" .. an executable program will have *many* byte instructions code/ope […]
Show full quote

Curious - what are you referring to by "online decompiler" .. an executable
program will have *many* byte instructions code/operands, and knowing if
one has changed would require some sort of reference to the original.
(On the x86, even "identical" operations can have different encoding)

https://dogbolt.org/

I just figured it might give an error, or it might show something else in that area that looks wrong.

I might still be able to help you a bit....

Even though the USB floppy won't work with ImageDisk, it might still be worth getting DOS to boot.
The "RUFUS" tool can make a bootable USB stick with a DOS floppy image... I've dones this a few times and it works!

I have a tool I wrote before ImageDisk that read/write diskette images via BIOS calls - it's nowhere near as capable as IMD as
it doesn't access the floppy controller directly, but it does work with USB drives, and I could modify it to do a couple of extra
things:

- Try seeking from both sides when it gets sector errors
- Keep going when it can't recover a sector (ie: get all the readable sectors)

A 3.5" 1.44m disk is 2880 sectors of 512 bytes each.
I could put together a tool which would let you select which of several images sectors are taken from to create
a final image - this would let you take multiple attempts to read and join up the good sectors.

The "trick" will be how to get the images off the booted DOS's RAM disk.
Easy if you have a serial port, doable without a second DOS system if your network interface is
supported by a "packet drivers" (or you can put a supported one in a slot), and doable to another DOS
system via parallel! - once you have them, you could work-on/reassemble them in DOSBOX.