Subject: Re: 40x CD-R without UDMA?
To: Daniel Carosone <>
From: Manuel Bouyer <>
List: current-users
Date: 12/17/2002 21:57:59
On Tue, Dec 17, 2002 at 10:54:42AM +1100, Daniel Carosone wrote:
> I had a rather urgent need to burn some CD's last week, and the
> most readily available burner was in the random pc shop 'round the
> corner.  I grabbed what they had, shoved it in a machine, wrote
> the CD's I needed and ran off to do what I needed them for so
> urgently.  All was good.
> A little while and a few other crises later, I had a moment to look
> at the thing a little more closely.  It's a "BENQ" 40x12x48 w/rw/r
> ide that probes as follows:
> cd1 at atapibus0 drive 1: <40X12, , 1.GE> cdrom removable
> cd1: 32-bit data port
> cd1: drive supports PIO mode 4, DMA mode 2
> cd1(pciide0:1:1): using PIO mode 4, DMA mode 2 (using DMA data transfers)
> Note no mention of UDMA support *at all*, which I find rather
> surprising.  I think you'd have to try pretty hard these days to
> not implement UDMA - and I rather doubt DMA-2 can sustain enough
> bandwidth for a full 40x burn. It has their equivalent of "burn

DMA2 can do 16MB/s, if my math is right 40x is 12MB/s (and 48x is 14.4)so it
can, but it has better be alone on the bus.

> The other thing to note is that after the probe, the pc's drive
> LED comes on and stays on - until the burner is used the first
> time.  It rather looks like something is not completing properly
> during the probe. I tried it as master alone on the bus too, no
> difference.

I used to have this on my PCs (with ATAPI ZIP too) and it was fixed by
sys/dev/ata/ata.c rev 1.17 for me.

Hum, I though this had been pulled up to 1.6 but it looks like it has not
been. I'm going to request a pullup.

Manuel Bouyer <>
     NetBSD: 23 ans d'experience feront toujours la difference