Re: Triton DMA

[Rogier Wolff]

Doug Ledford wrote:
> 
> > If there would be "current driven" drivers
> >around, that might make sense, but a SCSI driver simply needs to drive
> >the signal level to 0V or 5V.
> 
> You seem to forget that amperage and voltage are invariable partial elements
> to an overall equation that includes ohmage.
> 
> > Without termination however you get
> >interference from the bounce-back of the travelling wave front.
> 
> Without termination you get much worse than that.  You get an unreadable
> SCSI bus.  It is possible for a single TTL driver to bring on open circuit
> up to a 5 volt level.  However, knowing when 5 volts has been attained
> requires a reference ground (all of those grounds pins are used here because
> the ground reference between different power supply connectors could vary
> quite easily, especially when you consider external devices with their own

I stopped reading here. Total nonsense. The reason for those "extra"
ground lines is to create the transmission line effect. The
side-effect of creating transmission lines is that you have to terminate
the wires to prevent a bounce-back at the end.

					Roger.

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