Problems with Floppies and SCO XENIX-386 2.3.3

[Wu Liu]

/--paulz at sco.COM (W. Paul Zola) said...
| In article <178 at nat-3.UUCP> root at nat-3.UUCP (nat-3 System Administrator) writes:
| }
| }Hello --
| }
| }	I have a 25 MHz 386 clone running SCO XENIX-386 2.3.3 (I bought
| }2.3.2 and upgraded it with UFJ and various other SCO SLS's).  I have a
| }WD1006V-SR2 RLL hard/floppy disk controller.  I am having problems
| }writing to my 1.2 and 1.44 Mb floppies and the symptoms are these:
| 
| [ problems in using floppys deleted ]
| 
| The following article from the SCO Information Tools database should help 
| with your problem.   I'm posting because I think this may be of general
| interest.
| 
| ################## cut here ################ cut here ##################
| 
| Mkdev fd does not work properly with some video adapters.
| 
| KEYWORDS: mkdev fd video adapters 16 bit floppy disk filesystem root boot xenix unix vga paradise
| 
| RELEASE: SCO XENIX System V Operating System Generic
|          SCO UNIX System V/386 Operating System Generic
| 
| PROBLEM: Both 16 bit video adapters and the floppy drives use DMA channel
|          2. Therefore, when writing to, or reading from, a floppy disk drive
|          the video adapter controller may add or intercept characters from
|          the floppy disk data stream, thereby corrupting the floppy.
| 
| SOLUTION: Move the video adapter to an 8 bit slot.
| 
| ################## cut here ################ cut here ##################
| 
| I hope this helps you with your problem.
\--

Note that this doesn't necessarily apply to ALL 16-bit VGA cards, just
some of them.  It's pretty difficult to generalize, too.  It's been
my experience that Paradise cards are safe, as are Video 7s and the
new Trident 8900 clones.  One of the older Tseng ET3000 clone cards
(Orchid ProDesigner Plus) exhibited this problem, while an STB didn't.
I don't know about the newer ET4000s.  I'd guess that the more recently
designed VGA cards have a jumper or switch or something that will allow
you to configure the card accordingly without having to move it to an
8-bit slot.