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Three Floppy Drives In A Computer?

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DOS lives on!!

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Is it possible to have three floppy drives in one computer? I would like to put two 5 1/4 drives (one a 360k and other 1.2mb) and a 3.5 inch drive in it. Seems like it would save the hassle of switching out drives to copy files to different drives. Well....how would I make the BIOS support it? It's an older PC, a Gateway 4DX2-66E. Just another one of those weird ideas.:p
 
Certainly. The 5150 and 5160 could support 4 floppies as a standard configuration via the external drive connector on the floppy controller bracket.

On later systems with DTC or Ultrastor SCSI controllers for example, could support three (with a driver) on a single cable. Some versions of DTC controllers could even support four on one "flat" cable. N.B. you needed drivers for both of these.

Some third-party floppy controllers, such as Micro Solutions (Compaticards), DTK, Western Digital WD-1002 FOX, could support 4 drives and had their own BIOS extensions to do so.

There are also floppy controllers that support secondary I/O ports with their own drivers and BIOSes. I've got a 386 tower here, for example, with 6 floppy drives in it for duplicating. Each controller uses a different I/O port, DMA and interrupt, so up to 3 floppies can be accessed simultaneously. Very cool for copying to be able to write 3 floppies at the same time.
 
DOS lives on!! said:
Is it possible to have three floppy drives in one computer? I would like to put two 5 1/4 drives (one a 360k and other 1.2mb) and a 3.5 inch drive in it. Seems like it would save the hassle of switching out drives to copy files to different drives. Well....how would I make the BIOS support it? It's an older PC, a Gateway 4DX2-66E. Just another one of those weird ideas.:p
Click to expand...

Well, there was the Compaticard which could handle 4 floppy drives at one time. Some other controllers could do similar tasks. I also remember seeing somewhere a design that would allow 3 floppy drives on a standard floppy controller which incorporated a switch so only 2 drives would be active at a time but I can't find that link.

Otherwise, you can find an IDE controller card and one of the various IDE floppy designs (like the LS-240, Caleb IT Drive or Insite drive) or go SCSI and do much the same. Or track down an external drive enclosure of the correct flavor which will be slow and inconvenient but easy to find.

Some more commentary here http://www.seasip.info/VintagePC/floppies.html Thanks to Mr. Elliot for it.

One other issue to look for is drive bay clearance. At least on my Gateway 486E tower, a number of the bays were accessible only by removing the motherboard. Hopefully, your model has a better designed case.

(I have to remember to check if Chuck(G) is online when floppy questions are around. He produces correct answers while I am confirming my memory.)
 
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Yes! I happen to have 4 drives in 2 pcs. Both have aftermarket raid controllers. One is a CSC fastcache 64 other I forget. Look for ISA based raid controllers that work on early ibm xt/at pcs. Most them support 4 floppy drives. :D
 
Some ISA multi-I/O cards (the kind with IDE, floppy, parallel, and serial all on one card) let you change the I/O address of the floppy interface, so you could use them to add a third (and fourth) floppy alongside the the standard two.

I have a Prime branded card that lets you do it. Iirc you just needed to add a few lines to config.sys to tell DOS the second floppy interface existed.
 
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I hooked all three up to one cable that went into the motherboard. When I turned the computer on, the 3.5 drive lights up and checks itself. Then, both of the 5.25 drives light up at the same time and "check" themselves. The BIOS still won't show support for a third drive. The CMOS battery may be dead. Do you think I might need to get a seperate floppy controller card to make this work?
 
DOS lives on!! said:
I hooked all three up to one cable that went into the motherboard. When I turned the computer on, the 3.5 drive lights up and checks itself. Then, both of the 5.25 drives light up at the same time and "check" themselves. The BIOS still won't show support for a third drive. The CMOS battery may be dead. Do you think I might need to get a seperate floppy controller card to make this work?
Click to expand...

Which controller do you have in your 486-E? My Gateway shipped with an Ultrastor SCSI card that only supported 2 floppy drives; Ultrastor also had a very similar but much more expensive controller that could handle 4 floppy drives with the installation of a DOS driver. If you are lucky, you simply need a device driver. Otherwise, either get a second controller or replace your existing controller or use a floppy that does not connect to a floppy cable.
 
It will access the 3.5 drive on its own, but accesses both of the 5 1/4 drives at the same time. It's probably just a driver I need to find.
 
If you're willing to weave a cable a bit for the 3rd drive (I can furnish a diagram) and you have an onboard FDC that can support floppies without external buffers, you can often just run a single wire jumper to the floppy controller and add a driver. I've done this with Future Domain SCSI cards, for example. An example of an FDC that this works with is the National Semi DP8473.

The trouble with the "flat" 4-drive cable is that all drive motors run at the same time. A 3-drive "woven" cable doesn't have the same problem.
 
Could you post the diagram. At least I've gotten somewhere. When I first started, all three drives lit up, turned out to be the cable was plugged in upside down.
 
DOS lives on!! said:
I hooked all three up to one cable that went into the motherboard. When I turned the computer on, the 3.5 drive lights up and checks itself. Then, both of the 5.25 drives light up at the same time and "check" themselves. The BIOS still won't show support for a third drive. The CMOS battery may be dead. Do you think I might need to get a seperate floppy controller card to make this work?
Click to expand...

That sounds as if you've got both of the 5.25" drives hooked up as drive B:. On an IBM-style system where there are twists in the floppy cable, you can usually only get two drives on any one cable.

(In theory some controllers may allow three, by having the third drive jumpered as unit 3 and the other two as unit 1, but I haven't seen anything that does this).
 
Okay, here's the cable wiring for 3 drives:


Note that this uses pins 4 and 6 on the floppy cable (normally unused) as the drive
select and motor enable.

If you have a DP8473 in PLCC (most common) as your FDC, connect pin 4 on the floppy header to pin 1 (MTR2) of the DP8473 and pin 6 on the floppy header to pin 45 (DR2) on the DP8473. (The DIP package of the 8473 supports only two drives).

Hook up your drives and install the correct driver (I can supply one) for the third.

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From the readme:

EXFDRV.SYS is UltraStor device driver to support a third floppy
drive under MS DOS. You will need a copy of DRIVER.SYS file which
comes with DOS v3.2 and above. In the CONFIG.SYS file, the
following statements will be inserted:

"DEVICE=TargetDirectory\EXFDRV.SYS /1:xx"
"DEVICE=SourceDirectory\DRIVER.SYS /D:2/T:aa/S:bb/H:2/F:cc"

Please refer to the UltraStor SCSI Host Adapter manual for further
definitions of the above command line options.
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Alright, where do I put that file? C drive, WINDOWS, or System folder? Also, does it matter where I put those two lines of text in the CONFIG.SYS? Do I need DRIVER.SYS for this to work?
 
LOL. Its a dos device driver, so it would go anywhere you want, and you use it by adding it to your config.sys file. Add them after himem.sys and any stack/fcbs/lastdrive statements.

TY for uploading the drivers btw! I have a future domain controller somewhere around here I want to try this on now... :thumbsup:
 
Ah, that driver won't work unless you have an Ultrastor controller (it looks for a signature).

You might want to try a different driver (there are a couple wandering around this forum).

I'll see if I can find the Tulin driver that works with almost anything.
 
GADFRAN said:
Sure !

Kaypros could have four [4] !

Big advantages back then.

Check numerous posts on this site for lot more info !

Frank
Click to expand...

Golly Frank, I didn't know that a Kaypro 386 could have 4 floppies. (You know that PC 5150 and 5160 could have 4, don't you?) The OP has a 386.

I found the Tulin driver, but haven't checked it out yet.

However, you can check the operation of your hookup by using Dave Dunfeld's IMUTIL with the /4 switch (your 3rd drive will be C:).

Or you can create a DISKETTE.CFG file for CopyQM, FormatQM, 22Disk or Teledisk and check it that way.
 
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