Subject: Re: 3c509 again
To: None <dhess@CS.Stanford.EDU>
From: Mark P. Gooderum <>
List: current-users
Date: 06/30/1994 14:56:30
> I agree with the other poster that VLB systems with more than 2 slots at
> 33MHz should be avoided.  I would tend to blame your problems on the fact
> that your VLB board is outside VLB 1.0 specs before condemning VLB as a whole.
> I have one of the earliest VLB designs, a Micronics JX-30 (basically a
> Gateway machine), with an ATI GUP VLB and a Buslogic BT445S, and only 2 VLB
> slots; it has worked flawlessly in NetBSD, Linux, NT, Windows/DOS, and 
> OS/2 2.1.

And if you're running the VLB at more than 33MHz then you're asking for
it too since that's all the spec says has to be supported and many
cards have problems faster speeds (another good argument for a VLB
DX2/66 or DX4/100 instead of a DX/50 or a DX/66).

Finally, many "cheap" board makers have one or more of the slots not 
capable of Bus Mastering...slave only slots.  This works fine for some
IDE drive controllers and things like Video and memory boards, but doesn't
go far with a serious drive controller or network board.

Many boards will have a jumper enabling master or slave support and may 
require an extra PAL to support mastering, especially certain Taiwanese
486 boards that seem to have become very common.  Mine's one of these and I
know a dealer that has sold 100's of them.  Some come with it, some come
without it.  At least he's reputable enough to make the difference clear to
the customer and give a price difference (remember that Joe User is probably
never going to put more than a VLB VGA board and maybe an IDE controller).