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In article <Pine.OSF.3.91.960308133424.3754C-100000-100000-100000@leonis.nus.sg>,
>	Is there a method to use an external scsi to parallel converter 
>on a scsi zip drive? Know if such things exist, where I can get one?

Reposted for the fourteen quadrillionth time:



Several people have asked about the possibility of transporting the SCSI
ZIP drive to PC's having no SCSI host ... in particular whether there is a
way to use a parallel port adaptor.

The Adaptec [Trantor] MiniSCSI series won't work by themselves, since 
they draw power from the SCSI device and the ZIP drive does not 
provide TRMPWR.

However, Iomega still makes a similar adaptor, currently the PPA-3, which
is bundled with some Bernoulli drives. It costs about $180 and is available
direct, or from the special PC/Mac Connection Iomega order line.

There are two gotchas:

1. Cabling. The Bernoulli drives use standard 50-pin Centronics
connectors, and the PPA-3 is built to plug directly in. So, to connect a
Zip drive you have to make a custom cable having a female Centronics-50 on
one end and a male DB-25 on the other. This can be improvised using a "Mac
System Cable" and a F-F Centronics-50 gender changer.

2. Power. The PPA-3 is designed to draw power from the Bernoulli drive.
Not via the TRMPWR pin on the SCSI cable, but through a special mini phone
jack on the back. The PPA-3 has a short cable coming out of the side,
terminating in a mini phone plug. Iomega sells an optional power supply
for $25.

It's pretty obvious that the PPA-3 requires 5 VDC, tip positive, at some
small current draw. However, looking inside it is apparent that there is
**NO** regulation or reverse polarity protection on this plug. So be very
careful what you connect, or you could easily fry the PPA-3 ... a cheap
unregulated wall wart would be asking for trouble.

You could easily construct a y-cable to power the SCSI ZIP and the PPA-3
from the same Iomega power cube, though.

That being said - we rigged together cables and power this morning, and
tried the combination on a DOS machine having the Acculogic multi-io card
with SMC EPP port. Just typing "guest", it works exactly like a parallel 
port Zip drive, except that the SCSI ID on the drive is not 7 like the 
PP model. We achieved the same throughput under DOS as with the PP version 
on the same machine. Very easy and gratifying, if a little messy. 

This should probably work on the upcoming Jaz drive, etc.

-- 
Mike Schuster       |        schuster@panix.com | 70346.1745@CompuServe.COM
------------------- | schuster@shell.portal.com | schuster@mem.po.com