Re: Apple High Speed SCSI card manual/docs?

["Roger Johnstone" <rpj@thinkapple.com>]

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In article <376068D2.5B0C@seidata.com>, Jack Countryman
<jcountry@seidata.com> wrote:


>I've got an Apple High Speed SCSI card given to me...supposedly not
>working.  I no longer have a good one, a manual, or any docs for one of
>those cards.  I don't even recall what the four switches control
>anymore.  Doesn't the first one do DMA on/off (which setting is which?)
>and the others set scsi id (normally set to what...7...so as not to
>conflict with the drives' ids?)...or is my memory failing me?
>
>All help/leads appreciated.  Thanks.

Your memory is fine,

    switch 1  closed=DMA on  open=DMA off
                    

            switch
      2       3       4    SCSI ID
   --------------------------------
    open    open    open        0
    open    open    closed      1
    open    closed  open        2
    open    closed  closed      3
    closed  open    open        4 
    closed  open    closed      5
    closed  closed  open        6
    closed  closed  closed      7

The default setting for the card as shipped was all switches closed:DMA on
and ID set to 7.

hint:setting the card's SCSI ID to 2 adds a 3 second delay at startup before
the card checks the SCSI chain. An old 20MB hard drive I had was very slow
starting up and the card would miss it if the computer and drive were turned
on at the same time. Setting the card's ID to 2 solves this.

Roger.