PDA

View Full Version : JCC 4DR-14A / SUN 4310 8 Bit Floppy Controller



IBM Portable PC
November 21st, 2013, 03:38 AM
What's involved in making a FDC like this a secondary FDC?

i.e. How much hacking is needed to change the address the board appears at?

Thanks to Mike's blog here: http://www.brutman.com/forums/viewtopic.php?f=2&t=347 I see that this controller is one of the few to work with SDRIVE.SYS ( see http://www.seasip.info/VintagePC/floppies.html )
(You can download SDRIVE.SYS here, it's part of this package: http://www.pop-brb.de/download/treiber/exsys/ide.zip )

I've uploaded the FDC's manual here: https://drive.google.com/file/d/0B7bBJ4gXPp85RFhVUlc5anEwYlk/edit?usp=sharing

I can definitely see the need for an XTIDE style FDC project, which I know is underway.

Clem

Stone
November 21st, 2013, 03:53 AM
Secondary? It's already primary and secondary. Are you looking to install six floppies on one machine?

Chuck(G)
November 21st, 2013, 08:06 AM
Stone, this controller will use the primary port, DMA and IRQ only. That is, it works as a substitute primary controller--you have to disable any controller integrated on the motherboard or hard drive card before you can use it. I suspect that the on-board BIOS code is hard-wired to 3Fx,2,6 as well.

IBM Portable PC
November 21st, 2013, 12:02 PM
Secondary? It's already primary and secondary. Are you looking to install six floppies on one machine?

Good point!:whatthat:

modem7
November 21st, 2013, 09:01 PM
I've uploaded the FDC's manual here: https://drive.google.com/file/d/0B7bBJ4gXPp85RFhVUlc5anEwYlk/edit?usp=sharing
From there, I copied the Sunix SUN-4310 manual to http://www.minuszerodegrees.net/manuals.htm
Thanks on behalf of those who may use it in the future.

Chuck(G)
November 21st, 2013, 10:45 PM
Good point!:whatthat:

You're both missing the point. A primary floppy controller resides at port 3fFx (3F2-3F7 usually) and can support up to 4 drives. A secondary floppy controller uses a different port address, usually 37x and can also support 4 drives. With both a primary controller and a secondary controller, you can have support for up to 8 drives.

One of my system has three floppy controllers, each with 2 drives, but I could put 12 drives on it, if I had room.

For example, the 5150 floppy controller was primary and supported 4 drives (2 internal and 2 external).

The 4 drive per controller limitation is inherent in the NEC D765 (and clones) hardware and command structure (2 bits for drive select).