Subject: Re: Oooooh... IDE to Q-bus/Unibus adapters.
To: Allison J Parent <allisonp@world.std.com>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: port-vax
Date: 07/08/1999 00:33:37
On Wed, Jul 07, 1999 at 11:15:07PM -0400, Allison J Parent wrote:
> <> doing Qbus DMA is not so hard and if you can find a DRV-11B plus the prin
> <> for DRV11P DEC has done some of the work.  Even though the DEC chips may 
> <> scarce (other than stripping old boards) the functions are easily done us
> <> available TTL and CMOS or for those that can FPGAs.
> <
> <Okay, but you're not going to find a DMA IDE controller that's not PCI.  D
> <you see why I was going on about how you ought to be drawing the compariso
> <to cheap _PCI_ SCSI adapters?
> 
> Your not going to find a IDE controller for anything other than PC because 
> there is NO DEMAND FOR IT.  People don't do much design for other busses
> as there are no other busses in their field of view.  Doesn't mean it can't 
> be done.

Okay, so you're going to build a whole new IDE controller for Qbus.  Fine --
that certainly wasn't what I got from your initial posting.  Essentially,
you're building a Qbus to ISA bus bridge, since that's darned near what the
IDE wire protocol is.

It's not clear to me that this will necessarily be any cheaper than doing a
PCI bus bridge on an FPGA and just using a PCI bus multi-IO chip, but if
you're going to build a whole new board from scratch -- more power to you!