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Fire-Flare
May 26th, 2017, 12:40 PM
I have a floppy controller card that has two floppy headers on it, but no onboard BIOS.

I haven't come across many computers with ISA slots, but the ones I have tried seem hard-wired to use just two floppy drives.

Can anybody suggest a machine I might have better luck with?

krebizfan
May 26th, 2017, 01:30 PM
The IBM PC and XT can handle 4 floppy drives. The machine can't tell the difference between internal and external drives.

There was a clone from the mid-80s that made the ability to have 4 floppy drives with drivers to read unusual disks central to their marketing. I have blanked on the name though.

Which controller card do you have? Someone here might have a driver that lets you use the third and fourth floppy drives.

Stone
May 26th, 2017, 01:34 PM
I haven't come across many computers with ISA slots, but the ones I have tried seem hard-wired to use just two floppy drives.I thought all vintage computers had ISA slots. :-)

Even 486 boards had ISA slots as did some 586 boards (which aren't even considered vintage).

glitch
May 26th, 2017, 01:38 PM
ISA was still common on Pentium 3 and AMD Athlon machines. Still, most of those machines will only support one floppy drive in BIOS. I don't know if there exist OS drivers to allow access to more than two floppy drives (DOS, Win, *NIX, et c.).

krebizfan
May 26th, 2017, 01:45 PM
I thought all vintage computers had ISA slots. :-)

Even 486 boards had ISA slots as did some 586 boards (which aren't even considered vintage).

Many vintage computers did not have ISA slots. Some prefer computers where cards have convenient handles like QBus or Microchannel.

JohnElliott
May 26th, 2017, 01:51 PM
Linux will happily support four floppy drives on a plug-in ISA controller, without any BIOS support (Supposedly it will also support a second controller so you can have up to eight drives, but I've never got that to work). The method is to specify the types of the extra drives with 'floppy=<drive>,<type>,cmos' on the kernel command line -- or in /etc/modules.conf if the floppy driver is a loadable module.

In theory it should also be possible for Windows NT / 2000 / XP to support four floppy drives even if the BIOS doesn't, but unlike Linux I don't think there's a way to specify the drive types manually. So you'd probably have to get hold of a suitable DDK and compile a version of FLOPPY.SYS with hardcoded drive types. They do support four floppy drives if the controller provides its own BIOS.

Plug-in ISA floppy controllers will work on some Pentium II / III / Athlon motherboards with the appropriate slot, provided that the BIOS allows you to disable the onboard floppy controller. The Supermicro P6SLA and P6SBA support this, for example.

Fire-Flare
May 26th, 2017, 01:59 PM
The IBM PC and XT can handle 4 floppy drives. The machine can't tell the difference between internal and external drives.

Which controller card do you have? Someone here might have a driver that lets you use the third and fourth floppy drives.

I put an XT board out in the warehouse a few months ago but now I can't find it. (I hope it didn't get scrapped)

This is the controller I have: http://www.minuszerodegrees.net/manuals/Kouwell/Kouwell%20KW-530F%20-%20configuration.pdf

modem7
May 26th, 2017, 03:05 PM
I have a floppy controller card that has two floppy headers on it, but no onboard BIOS.

This is the controller I have: http://www.minuszerodegrees.net/manuals/Kouwell/Kouwell%20KW-530F%20-%20configuration.pdf
Chip U2 will be the KW-530F's BIOS.
Or are you saying that someone has removed the chip ?

Chuck(G)
May 26th, 2017, 04:14 PM
Yes, the Sysgen Omnibridge and WD 1003FOX and the four drive version of the DTK Mini-micro FDCs all have BIOS support for 4 floppies.

The MicroSolutions CompatiCard IV not only has support for 4 floppies, but includes drivers to add additional cards. I have a system with 6 floppy drives; 2 on each controller--I run SyDupe on this setup to write/read 3 floppies at the same time. Can't do any more than that because you run out of 8-bit DMA channels. If I had room in the box, I could run 12 floppy drives--all supported under DOS.

KC9UDX
May 26th, 2017, 06:19 PM
Every Amiga motherboard supports four drives, with no hitches.

All Commodore 8-bit motherboards will all support 24 floppy drives, IIRC.

Xacalite
May 26th, 2017, 07:19 PM
Microid Resarch BIOS used in some 486 and early Pentium boards has support for 4 FDDs - http://www.esupport.com/techsupport/docs/mrb33x.pdf
However, you probably don't need BIOS support, extra drives connected to such a card should work with SDRIVE.SYS, as described here - http://www.seasip.info/VintagePC/floppies.html