On Sat, Jun 20, 2020 at 10:12:51PM +0300, Mike Banon wrote:
Well, I suspect for these use cases it'll be *alot* easier to add emulated harddisk support instead.
It requires coding for SeaBIOS
Same is true for superfloppy support. And testing this is much more difficult. Physical floppies are pretty much dead these days, and I doubt qemu can properly emulate all those tricks which superfloppy formats are using.
Also: why invest much effort to squeeze a limited amount of additional capacity out of floppies if you can effectively remove all your capacity issues by just using hd images instead?
- asking the floppy OS authors to
release it as an HDD image (how many will do this?).
Don't they already do this? How do you boot a floppy OS without a floppy drive? Don't they have usb stick images for that? Such an image effectively is an hd image ...
Meanwhile, support for floppies is already there - including the double sized ones (2.88MB), it just needs an improvement
The superfloppy improvements I remember (probably incomplete):
(1) Most floppies and drives are tolerant enough for a few extra tracks, so use -- say -- 82 instead of 80 tracks. (2) Tweak timings a bit to squeeze one or two more sectors on each track. (3) Use 2048-sized sectors instead of 512 (less sync info needed -> more space for data). (4) Booting from 2048 sector floppies doesn't work, so use a 512-sector format for track 0 with boot block and superfloppy driver and 2048 for all other tracks.
(1) looks easy, maybe even works without code changes, and given this is all virtual anyway if we are talking about floppy images you can probably add more than just 2-3 tracks without much trouble. (2) has effects on chs calculations, so I guess that one doesn't work with seabios right now. (4) is hard for images, and (3) without (4) is useless if you want boot from these floppies, so I guess that isn't used any more these days?
take care, Gerd