I would like to know this as well. Are you limited to ISA or do PCI floppy adaptors exist as well? Could you boot off such a bus floppy? Do they work in DOS without drivers?

computergeek92 wrote:

Is it possible to use 3 floppy drives in a computer system? (One 3.5 inch, one 5.25 inch, and one Gotek USB emulated floppy drive) Could I use an ISA floppy controller to use more floppy drives alongside the single mobo floppy port?

Yes, you can. But it's not easy on computers newer than the PC/XT.
It's quite complex to explain in a few words..
Involves a modified floppy cable and/or a second controller on a different port and driver.sys.
Either way, it's at least possible to add a logical floppy drive.

Errius wrote:

I would like to know this as well. Are you limited to ISA or do PCI floppy adaptors exist as well? Could you boot off such a bus floppy? Do they work in DOS without drivers?

ISA or LPC bus for DOS / booting. It depends, on a PC/XT you can have up to 4 drives, I think.
The 3rd-floppy method involves a modified cable and also works on PC/ATs as far as I remember.
Can't tell the details right now. I saw a schematic in a computer magazine from the late 80s/early 90s.
I'll search for it, if you want. But this takes time. I don't have access to them right now (they're boxed).

Never mind, I was hoping for something simple. There's also the issue of later mobos that support just a single A: floppy with no option for B:

Ok then. Sorry, if my response discouraged you. 🙁
But I also have a good news, the missing option for B: is a pure BIOS limitation and can be patched.
The average on-board floppy controller is a derivative of the good ol' Shugart interface and can drive a second (or third) floppy with no problem.

The reason I said it's complex, is because it depends on the type of computer system you have, so theres's no general answer.
As far as I know, there are several ways to add more floppies to a PC..

For example, the orignal PC 5150 had the ability to use up to 4 drives (set via jumpers).
I don't know why, maybe because it did not support fixed disk drives and thus the letters "C" and "D" were not assigned.
If we think about it and the fact it also came with an cassette port, this idea isn't too implausible.

On the PC/AT (and its successors) however, things are a bit different.
The AT-style BIOS reserves the "C:" drive for a hard disk and it's CMOS utility doesn't have the ability to setup a third or fourth floppy drive.
This is where driver.sys can help. If you made a special floppy cable and load this driver, you can setup a logical drive and assign it to a free drive letter you wish (like "X" or "Y").
However, I don't know if this works for low-level routines used by games or copy utilities.

I don't know for sure, but this driver.sys trick may also work with a second floppy controller.
If one of those old 8bit dinosaurs had jumpers, you could set it to another port address.
Or if you can get a floppy based tape controller, you can use that aswell.
Then, you only need to patch driver.sys to look out for that non-standard port (a hex editor is all you need).
But this is pure speculation, maybe I'm wrong here. I know a bit about CP/M machines, but my knowledge about PC/XT class machines is next to zero.

And there's also the PS/2 line, which uses a different kind of BIOS.
I have no idea whether or not it supports more than two floppy drives, but I've seen a lot of external drives for it (possibly SCSI based ?)

After all, the easiest way for you is probably to use one of those 4-drive floppy controllers with their own BIOS.
They sometimes show up on eBay, but I've never got one myself.

Here's a bit of something to read. Maybe it can help you further.

More Than Two Floppy Drives

The Floppy Interface in Waveterm A und B

The plan is having those 3 drives on a Pentium II or as early as 486 and have Windows 95C.

The first link above me claims I should look for a 4-drive floppy controller. So I guess i'll be using an early 486 that takes I/O add on ISA cards. Since I don't want to disable the onboard floppy. Would anyone know any 4 port cards that support 1.44 and 1.2 drives?

its stupid easy:

5.25 floppy & usb emulator on the floppy controller, use a usb floppy drive for the 3.5. If you don't (or cant) use a usb floppy, then buy an LS-120 drive. They are MAGICAL for recovering 3.5" floppy disks and if you are so inclined, the 120mb disks can be used to transfer large files.

@jo22

The PS/2 computers EASILY supported 3 floppy drives. The bios treats the first 2 drives normally, and the 3rd is treated like a CD drive. (in dos) I've never had any issue.

computergeek92 wrote:

The plan is having those 3 drives on a Pentium II or as early as 486 and have Windows 95C.
The first link above me claims I should look for a 4-drive floppy controller. So I guess i'll be using an early 486 that takes I/O add on ISA cards. Since I don't want to disable the onboard floppy. Would anyone know any 4 port cards that support 1.44 and 1.2 drives?

I don't know for sure, but I think I've seen such a card on eBay a while ago. Complete with box and manual.
It was a 16bit ISA card with a 27256 or 27512 EPROM chip (dated '93 or '94, cant' remeber).
It had two modern floppy connectors (no egde connectors) and supported upto 2.88MB, I think.
Anyway, most 16bit controller cards should be new enough to have support for 1.44MB drives.

luckybob wrote:

its stupid easy:
5.25 floppy & usb emulator on the floppy controller, use a usb floppy drive for the 3.5.IIf you don't (or cant) use a usb floppy, then buy an LS-120 drive. They are MAGICAL for recovering 3.5" floppy disks and if you are so inclined, the 120mb disks can be used to transfer large files.

Not a bad idea, especially since the usb emulator probably doesn't have switches to set a drive number.
And thanks for that tip with the LS-120 drive! Have to search for one now.

luckybob wrote:

The PS/2 computers EASILY supported 3 floppy drives. The bios treats the first 2 drives normally, and the 3rd is treated like a CD drive. (in dos) I've never had any issue.

Thank you, that's good news! 😀
I wished I had a Model 80. Still looking for one. If only shipping that giant wasn't so expensive..