Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
In article <2mlbs1FopdqfU1@uni-berlin.de>, "Egil Solberg"
<egilso@hotmail.com> wrote:
> Michael Mueller wrote:
> > Hi Group,
> > is it possible to get 2 Floppies work (drive A + B) each 3,5".
> > I got only a in BIOS and device manager.
>
> Interesting. I looked through the manual and there is not much sign of dual
> floppy support. Normally one would see an option like "swap floppy drive",
> but this is an AMIBIOS, so I don't know if it usually is present there.
> One sign of dual floppy support: boot order: "first floppy drive" (then
> there should be possible to use second one).
>
> Are there 2 floppy connectors on the floppy cable? Does the cable have the
> necessary "twist" so the controller can understand that there are 2 drives?
> Have you tried a good old floppy cable? Is the cable insertion and
> orientation ok?
The floppy is considered a legacy device, and there are some daring
(but stupid) motherboard manufacturers who have eliminated it completely.
There is presumably some standard that says the floppy can be eliminated,
and for any motherboard manufacturer, there is a constant tug-of-war,
between the need to "advance" by removing old interfaces, and the need
to keep consumer loyalty, by continuing to allow users to reuse their
old hardware.
Now, in terms of the hardware, there are several vendors of Super I/O
chips, and their approach to the floppy issue is interesting. Some
older chips have definite, uncompromised support for two floppies.
When you look in the device datasheet, you can see two motor control
signals and two drive select signals. In this example schematic, on
page 3, you can see a 34 pin connector called FDC-Conn, and it has
MOTEA#, DRVB#, DRVA#, MOTEB# on pins 10,12,14,16 respectively.
http://www.iteusa.com/pc/8702&8712CG_v1.0.PDF
Later ITE chips multiplexed some of the floppy signals with the SIR/CIR
Infrared interface, which means if you had an Asus motherboard with a
SIR/CIR header on it, that virtually guaranteed that the floppy connector
only had signals for one floppy.
Now, in the Winbond case, they do something similar. The P4C800 uses
Winbond W83627HF (no hardware monitor), while the newer P4C800-E Deluxe
uses Winbond W83627THF (hardware monitor). The THF has reduced
functionality for the floppy.
http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627thf.pdf
http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf
Unfortunately, Winbond has seen fit to only continue to allow one of
the datasheets to be downloaded.
The 627HF has MOA#, DSB#, DSA#, MOB# on IC pins 4,5,6,7.
The 627THF has MOA# , DSA# on IC pins 4, 6 .
This means the P4C800-E Deluxe only has hardware signals for one floppy
on the 34 pin FDC connector.
Both Winbond chips also support the ability to connect a floppy
drive to the parallel port.
On PDF page 122 of the 627hf.pdf document (which when you check the
title, is the datasheet for the THF now - a very smooth move on
Winbond's part), there is also a way to connect a floppy drive to
a parallel port. The 627THF only has MOB2 and DSB2 signals, meaning
a single floppy can be connected to the parallel port. The 627HF,
in a similar diagram, has MOA2, DSA2, MOB2, DSB2 signals, and supports
either EXTFDD mode or EXT2FDD mode (two floppy drives on the parallel
port).
So, in summary, P4C800 has hardware signals to control four floppies,
two on FDC connector, two on parallel port. The BIOS appears
to support one floppy drive on the FDC connector.
P4C800-E Deluxe has hardware signals to control two floppies,
a single drive on the FDC connector, and a single drive on the parallel
port. The BIOS appears to support one floppy drive on the FDC connector.
I haven't mentioned the BIOS here, and have no idea how you go about
determining what gets enumerated about the Super I/O chip, and what
the OS is told about the hardware. It would be purely a guess, to
say the parallel port floppy is only a feature at the Windows level,
because I cannot imagine the BIOS being smart enough to probe the
parallel port, to see if a floppy is connected.
Until now, I'd never heard of this "hang a floppy off the parallel
port option", and again, have no idea what software and/or
adapter cable is required to make that work. There is a warning in
Google, about the wiring of these things not all being the same,
so until you've done a lot more research on this EXTFDD option,
don't connect the first such floppy drive you can find.
As another poster mentioned, it would be safer to connect a floppy
drive via USB, because presumably that is what Intel wants us
to do
HTH,
Paul
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