There's some interesting reading if you Google [how to read 5.25 720k floppy]

I was googling "media descriptor byte hddd floppy" and got nowhere...

>Those were the semi Wild West days where there were lots of different drive parameters for the various diskette formats e.g. http://www.retrotechnology.com/herbs_stuff/drive.html#720K . As I see it:
>
>- the drive must be capable of running using the parameters expected by the floppy media
>- the BIOS must be capable of setting those parameters. ISTR with old BIOSs (at least with PCs) you could select the floppy drive type from a list. But if your format isn't in the list you're basically SOL

It just worked on all machines at the time (1989-1994), and then we somehow overnight switched to 3,5". So I guess either Dos3.1 (up to 5.00) had some code to recognize that type, or the BIOSes regularly did that - all automagically, didn't have to touch any settings.

>An old machine may be the best bet to get a combination of drive + firmware that can read your floppies. If you can boot it into DOS at least, you should be able to install the NDIS TCP/IP stack for modern-ish networking. I think 20 years ago was around the time that NICs were just starting to be available with 10BASE-T, or combination BNC/10BASE-2 and 10BASE-T. There were also some hubs/switches that were combination BNC/UTP so if you can only find a BNC NIC you might be able to use one of those combo hubs to connect to your current box.

My best bet would be a machine from about 1994 or 1995, which would still be able to read this and would have a proper IDE disk interface. I have some 3-4 old IDE disks in the bottom drawer which are probably still operable. I discarded them when they became too small or developed a few bad sectors. Storing a few dozen megabytes on one of them shouldn't be impossible, and I still have a SATA/IDE USB disk drawer to stick them in to connect to current box. Failing that, I guess I still have some old NIC somewhere, or can lay my hands on some of the early CAT5 cards which would fit those boxes. The network software would be a worse hurdle, but I guess some old DOS 7 (from Windows98) boot floppy may still be around. Funny, though, that there would be such a disconnect between generations of hardware - we abandoned floppies, zip drives, serial ports, centronix ports, even CDs are rare nowadays, BNC and IDE... and each one was living in parallel with its descendant for a number of years, and all machines were a mix of the old and new. I remember time (2000-2003 or so) when the only reason I had a floppy was that that was the mandatory format for daughters' homework. Then all of a sudden homework was to be either printed or emailed and nobody mentioned floppies.

>If the floppies were something else (e.g. CP/M) that could be tricky. CP/M machines for one basically had no concept of data transfer to dissimilar systems. Although Googling there seems to be Kermit clients for CP/M FWIW. You'd likely be looking at serial comms. FTP is likely too much to ask for, maybe some BBS software?

Did that already. And not on my floppies - whatever I did on CP/M was routinely moved to PDP and later to VAX via some VT52 type connection, i.e. simple serial. I remember that I once, later, came back to that same VAX to port some data to a PC - using some report-to-text, then getting that file via Telix or other terminal emulation and catching the output into a log file and then extracting data from there. But there's an extra story - I had a request from a customer (a bank!) to help them transfer some data from a CP/M floppy to a PC. Which I then investigated and found a solution and then couldn't do anything - how do you charge them for 15 bytes .com file which I downloaded from BBS? Still have that one, it simply disables the media descriptor byte check so that it returns OK every time. And then it read the 640K floppies from CP/M without a hitch (ok there was one - it read the slack too, disrespecting the actual file length and taking whole sectors). Tried to apply that on the DOS VMs that I had, but it seems to work at hardware level, not the emulated hardware level... so, no dice.