🚀 go-pugleaf

Paul Womar <Newsmaster@pwomar.demon.co.uk> wrote:

> > Guess what, the Mac plus doesn't supply this voltage
> > so even if you use plug terminators your SCSI chain
> > still can't figure out that anything is connected to it.
> 
> If thie voltage is the TERMPWR can you not just enable it on more than
> one of the drives attatched?

This as they say is the long and the sort of it.

Someone else posted details of SCSI spec for SCSI 1 (as used on
a MAc PLus) which as I said stated that

All signals not defined as RESERVED, GROUND, or TERMPWR shall be
terminated at both ends of the cable.  The implementor may choose one of
the following two methods to terminate each end (see figures 9 and 10):

   a)     The termination of each signal shall consist of 220 ohms
(+/-5%) to the TERMPWR line and 330 ohms (+/-5%) to ground.

As I have already said the Mac Plus does not supply this logic line
level (+5v). 

Now Macs including the Plus have an internal terminator so that takes
care of one end of the connection. The other end of your SCSI chain
needs to have some sort of access to a +5V/ TTL level / Logic Line call
it will for the the other set of terminators.

If as some else has suggested already have a