Re: Slowing down CDROM drives (was: Re: ATAPI CDRW which doesn't work)

From: Rogerio Brito (rbrito@iname.com)
Date: Sun Feb 11 2001 - 13:20:47 EST


On Feb 10 2001, Pavel Machek wrote:
> Hi!
>
> > ioctl(cd_fd, CDROM_SELECT_SPEED, speed);
>
> Does this actually work? I helped my friend with partly broken cdrom
> (worked only at low speeds) and it did not have much effect. It did
> not make my cdrom quiet, either, AFAI can remember.

        Well, I wrote a little program that just makes this call that
        Jens told me about and it worked perfectly with my hardware --
        using my CD-ROM drive at speed 1, 2 or 4, it works quietly and
        I can listen to MP3s at volumes that I couldn't earlier.

        OTOH, it seems that a paradox is happening: this very same
        drive has some problems (not always reproducible) reading some
        CD-RW discs when it operates at very slow speeds. In this
        case, the best that I can do is to let the drive accelerate as
        much as it wants and then it works ok.

        BTW, Jens, what is the way to set the drive back to its
        maximum speed, without limits? Where could I read more about
        the subject (that is, this and other ioctl's) without annoying
        you? I'm a moderately competent C programmer (only
        moderately), but I know *nothing* about the kernel.

        []s, Roger...

-- 
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  Rogerio Brito - rbrito@iname.com - http://www.ime.usp.br/~rbrito/
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This archive was generated by hypermail 2b29 : Thu Feb 15 2001 - 21:00:17 EST