If you have a board that works, but not with the addresses and irq you'd like,
you can easily fix that with an Xacto knife and some wire soldered where it
should be, rather than where it is. You may need an inverter to "fix" the
address sense. The primary IDE is at 1F0,,1F7 + 3F6 + FFA0..FFA7, the
secondary is at 170..177 + 376 + FFA8..FFAF. If you can't find a jumperable
board that (a) allows you to disable one of the two ports, if there are two,
and (b) select the primary/secondary location, then you can easily fix that.
You know about the interrupts, and they can be switched easily.
It doesn't matter, BTW, what the BIOS does with CDROMS, as the early '486's
didn't recognize CDROMs anyway, and Windows 9x see's 'em whether the BIOS does
or not.
Dick
----- Original Message -----
From: "ajp166" <ajp166_at_bellatlantic.net>
To: <classiccmp_at_classiccmp.org>
Sent: Saturday, May 04, 2002 7:56 AM
Subject: Re: ISA/486 Board Question
> From: Fred deBros <fdebros_at_verizon.net>
> >Is there an ISA card that has the IDE irq assignable to any IRQ?
>
>
> Older ones did. IDE IRQs were 15 and 14.
>
> >U guessed right: I'd like to stick a secondary ide drive (CDROM
> >obviously) into a 486 that has only one ide (IRQ14)drive, but no plug
> >for a secondary drive, and no, I cannot use the ide cable as it is a
> >laptop, but yes, it has the bus connected to a dockstation. And yes I
>
> yes you can. I've done it. one of my 486boxen has 3 CDroms and
> a 500mb IDE disk. It serves as a CD server running Win95.
>
> Some of the real early 486s the bios was a bit poor but most of the
> better ones it's been no problem. FYI: for the CDrom you simply do
> nothing at the bios level and it's the OS that has to find and install
> the CDrom. If the cdrom is a standard the win95 drivers will do though
> I've had a few oddballs that I had to use the driver supplied with
> the drive.
>
> Allison
>
>
>
Received on Sat May 04 2002 - 22:08:21 BST