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WTB: PCI floppy controller

H

haightc

Experienced Member
Joined
Jan 13, 2016
Messages
51
Location
SeaTac, WA
I am looking for a PCI floppy controller. I understand these are hard to come by but I thought I try asking. I would like to add 3.5 and 5.25 support to my modern PC that doesn't have built controller.
 
GiGaBiTe pretty much summed it up. I have an older PCIe mobo with a 790 series chipset and it has native support for IDE and floppies. Caveat: You can use any floppy format you wish but only for one drive. I set it up with a 5.25 and then use a USB 3.5 floppy.
 
haightc said:
I am looking for a PCI floppy controller. I understand these are hard to come by but I thought I try asking. I would like to add 3.5 and 5.25 support to my modern PC that doesn't have built controller.
Click to expand...
In lieu of a floppy controller you can use two (or even more) networked floppy drives on your modern PC. If you share them you should be able to use them on your PC that doesn't have or support them. I know I do.
 
...but I believe that such FDCs are still wired into an ISA bus. Even if that ISA bus isn't expressed as an actual slot, it's present.
 
Chuck(G) said:
Those are more common than you'd think on even later boards (P4, AM3+, etc.).
Click to expand...

A P4 is a later board? The last P4 was released over 10 years ago lmao.

Floppy support died out pretty much completely by the time the LGA1155 and Sandy Bridge came out. Some early AM3+ boards had floppy support, but it died out later.

There are a couple of LGA1155 boards with floppy drives, but they're usually buggy and junk low end boards like this one:

https://www.newegg.com/Product/Product.aspx?Item=N82E16813157253
 
bear said:
...but I believe that such FDCs are still wired into an ISA bus. Even if that ISA bus isn't expressed as an actual slot, it's present.
Click to expand...

Incorrect.

Modern floppy controllers integrated into the Super I/O chip run on the LPC bus.
 
There have been various posts on related threads that have stated that P3 was the end of the floppy-controller motherboards. So yes, P4 is later than P3. I did say "later', not "modern". Don't confuse the two term. A 1401 is later than a 650. Neither is recent nor modern.

The problem is that legacy floppy controllers depend on legacy 8 bit DMA as well as being pretty much wedded to IRQ 6 and I/O port addresses 3F0-3F7. So it's necessary for the chipset to support the ISA conventions. Sure, you could probably marry a floppy controller to other conventions, but no legacy software would work with them.
 
I recall seeing one awhile back, can't recall the manufacturer. Then there was the Catweasel Mark IV, which was good for multi-platform use. A true floppy controller would be ideal, but I do have a 486sx with a 5.25" drive. I have a Atari 800XL I still use and there is something nice to me about using an actual floppy disk. older floppy drives are fortunately pretty rock solid along with their media fortunately. My tower has an empty unused 5.25" bay and unconnected 3.25" drive, that would be nice to populate. I might just end up getting a kryoflux or FC5025 later down the road, but as I was saying I would prefer a real floppy controller.
 
A PCI floppy controller is possible mind you. Most if not all are an I/O based design, and all you need that's complex to hook it up with is a ASIC controller for the bus when using something like PCI Express. Good luck doing the following things though;

1) Trying to find any modern motherboard that has flexibility with option ROMs while ports 3F0-3F7 are available
2) Trying to get 8-bit DMA to even work
3) Trying to work around IRQ's and timing sensitivity

Basically, what Chuck said.
 
I have a PCI multi IO card. it has 2 IDE and a floppy controller as well as the normal 2 serial and 1 parallel port.
A quick look at the card and it appears to have jumpers to enable or disable everything so it could be set to enable only the floppy controller.
http://arvutimuuseum.ee/th99/c/E-H/20876.htm

My suggestion is to look for a PCI multi IO card and if you cant disable the unwanted features of the card disable the ones on the mainboard.

Edit: I just did a search on ebay and couldn't find one. Maybe they are not very easy to find, so my alternate suggestion is to install a 5.25" in the machine and use a cheap usb floppy drive for reading 3.5" disks.
 
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Woz was able to make a floppy controller using 74 series logic, 256 *bytes* of ROM, basic motor control and the 6502 CPU doing the bit banging, you don't need an ASIC to make a floppy controller.

If you could get a PCI card with an FPGA on it, you could do everything. I found a VHDL for a floppy controller:

https://pastebin.com/w0S40FV3

Though it's read only.
 
Okay, I'll modify my response by saying that there were some PCI cards with floppy capability, due to their inclusion of a PCI-ISA bridge IC. At least two models can be used on either PCI or ISA buses. They're extremely rare in the wild and I'm not even certain that they're compatible with most motherboards--and, quite possibly, not legacy FDD compatible (i.e. require drivers). Note that these boards all have the various functions that are handled on a modern motherboard by the Southbridge/SuperIO combination.

FWIW, here's the list:

GIGABYTE GA-107
GIGABYTE GA-108
SUNIX 5249P
TYAN S1363-004
TYAN S1366

If anyone has experience with these with contemporary PCI-equipped motherboards, I'd like to hear about it.

The trick isn't making a floppy controller; it's making one that legacy software understands. In other words, "can I run ImageDisk on this controller?" That VHDL that John pointed to is not legacy-compatible--and it doesn't write.

If you want a floppy controller, and don't mind writing software for it, any reasonably powerful MCU (say, ARM Cortex M3 or M4) with sufficient memory can do it. Hang a USB or Wifi interface off of it and Bob's your uncle. I read floppies routinely using an M4 MCU, but nothing, other than my own scribbling, is compatible with it. Legacy floppy drives are largely simple, brain-dead devices and you don't need much to interface to them.

After all, the "Gotek" floppy emulator works in a similar manner using a low-end STM32F105 Cortex M3 MCU--and it even implements a USB host interface for the flash drive and sells for about $20-30 shipped.
 
I have a ga-108 in front of me right now and it uses the standard ports.
The card uses the common UMC um8663 ISA Super IO chip. There is another chip I don't recognise but I assume it acts as the PCI/ISA bridge.

The card was in a machine with a PCI motherboard that lacked an on board Super IO, special drivers or BIOS support was not needed because everything was on the standard IO ports.
The only driver needed was for the IDE DMA mode.
 
David_M said:
I have a ga-108 in front of me right now and it uses the standard ports.
The card uses the common UMC um8663 ISA Super IO chip. There is another chip I don't recognise but I assume it acts as the PCI/ISA bridge.
Click to expand...
What kind of system was this in? Something "modern"-ish or an early PCI PC? Does it work with tools like ImageDisk?
 
David_M said:
I have a ga-108 in front of me right now and it uses the standard ports.
The card uses the common UMC um8663 ISA Super IO chip. There is another chip I don't recognise but I assume it acts as the PCI/ISA bridge.

The card was in a machine with a PCI motherboard that lacked an on board Super IO, special drivers or BIOS support was not needed because everything was on the standard IO ports.
Click to expand...


I also have a GA-108 here, but I'm not able to figure out how this card works. I can use only the IDE function -all other ports are not recognized. Could you give me a hint? All enable-jumpers are set correctly according to the th99 page.
I'd like to use the card with a UMC 8881F based 486 PCI board without onboard I/O-section.

btw there is no PCI/ISA bridge chip on this card. CMD 640B is an ordinary dual PCI IDE controller chip.
 
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