ElectroSoldier wrote on 2023-09-28, 02:13:

I have an adaptec SCSI card that has a floppy controller on it but that is an ISA bus card. I was wondering if there is something similar for the PCI bus?

Normal FDC uses ISA DMA - pretty much impossible on PCI.

Or maybe a 5.25" SCSI floppy drive?

Software support was poor even back in the era - Teac FD235-HS SCSI floppy

There's a buslogic PCI SCSI card that lists floppy support... but I don't see a 34 pin interface on it. Therefore I wonder if it has special onboard BIOS extension for handling SCSI floppies... or not and a mistake in tech specs has just been copy pasted for decades.

BitWrangler wrote on 2023-09-28, 15:16:

There's a buslogic PCI SCSI card that lists floppy support... but I don't see a 34 pin interface on it. Therefore I wonder if it has special onboard BIOS extension for handling SCSI floppies... or not and a mistake in tech specs has just been copy pasted for decades.

Perhaps it means SCSI floppy drives.
I noted it earlier during Windows NT setup driver loading.
But I have never seen one.

Grzyb wrote on 2023-09-28, 07:12:

Normal FDC uses ISA DMA

its wired to ISA DMA controller, but its not mandatory https://wiki.osdev.org/Floppy_Disk_Controller … _Data_Transfers
I seem to remember a HP Omnibook without one and working floppy https://www.cs.hmc.edu/~fleck/iowa-lab/omnibook.html It even runs win95 and apparently floppy works there. Some funny quirks tho: https://www.elhvb.com/mobokive/edwin/laptops/ … ce/OB600_fg.pdf

Undelete in File Manager causes GPF or Divide by Zero Overflow- due to no DMA
Use the extended DOS tools.

No DMA wont be a problem for software going thru bios interrupt routines.

BT-956CD and variants is the BusLogic card I mentioned.

edit: Hmmm manual is on archive.org https://archive.org/details/manualzilla-id-68 … ge/n33/mode/2up and at a quick scan all I see about floppies is it needs a normal floppy drive for driver install, and that it supports a config switch for removable media so the OS doesn't freak out when you change disks.

Another idea occured. Floppy Tape drive manufacturers started making alternate address floppy tech controllers for their tape drives so they could be used independently of floppy controller, and maybe they got a feature or two extra... the ones I have seen have been ISA... I'm just wondering if floppy tape drives lasted long enough that they made a PCI version... it would however need a lot of messing around to access a floppy drive plugged into one and best you might hope for is a dump of contents or image rather than an an online filesystem.

I dont know if someone already mention, but with USB 3.5 floppy i have very good support using omniflop as driver

http://www.shlock.co.uk/Utils/OmniFlop/OmniFlop.htm

I read very weird formats without problem

I use this cheap addaptor from ebay