[filmscanners] RE: CD RW Problem

["John Rossi" <cjrossi1942@attbi.com>]

Austin . . .thanks for the good explanation.  My Sony CD-RW CRX140E uses an
IDE bus  (EIDE) and has the option of enabling or disabling DMA.  It would
appear that disabling DMA would slow down the (read?) write process.  Would
it also tend to eliminate write errors caused by interruptions in the write
process?  John

-----Original Message-----
From: filmscanners_owner@halftone.co.uk
[mailto:filmscanners_owner@halftone.co.uk]On Behalf Of Austin Franklin
Sent: Saturday, October 12, 2002 9:37 PM
To: cjrossi1942@attbi.com
Subject: [filmscanners] RE: CD RW Problem


DMA means "Direct Memory Access", and if implemented properly, can speed
data transfers, simply because it doesn't read the data from one place,
store it, then write it out to some place else.  What DMA does, is directly
transfer the data between the two devices without any intermediate storing
of the data.

DMA is an older architecture concept...and primarily is used with IDE drives
and ISA (as in the ISA PC bus), and it's basically what's called a "third
party" data transfer scheme, because there is a specific DMA controller that
does the accessing of the source and the destination.  A mailman can be
considered the DMA engine of a DMA scheme.

PCI based disk controllers don't use DMA, as it's not a concept PCI has, PCI
uses a master scheme where the disk controller is actually the master, takes
over the system bus, and transfers the data directly to where it needs to
go.  No third party is involved...  Like you delivering your own mail.

Sorry that came out somewhat disjointed, but the bottom line is IDE drives
do use DMA, as the IDE "protocol" is basically an ISA bus architecture...but
whether it will help or not, is really architecture (motherboard, chipset
etc.) dependant...

Austin

> DMA, as I understand it, usually helps to prevent errors with burning
> CD-R/RWs as it speeds up data transfer from and to your harddrive...
> This is not my area of expertise, but that's how I remember it, at least.
>
> Art
>
> John Rossi wrote:
>
> > Mike . . . .  My CD burner is 4X which do not seem to be a
> problem finding.
> > I have updated my version of  Easy CD Creator, I will see if
> that makes a
> > difference.  I have also turned off the DMA option on my CD
> burner on the
> > advice of Dell.  The Dell tech said it might eliminate write errors(?).
> > John
> >
>
>
> ------------------------------------------------------------------
> ----------------------
> Unsubscribe by mail to listserver@halftone.co.uk, with
> 'unsubscribe filmscanners'
> or 'unsubscribe filmscanners_digest' (as appropriate) in the
> message title or body

----------------------------------------------------------------------------
------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title
or body

----------------------------------------------------------------------------------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe 
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or 
body