Classic mac fun (and some questions)
trag at io.com
trag at io.com
Thu Jul 9 15:05:12 CDT 2009
From: "Jeff Walther" <trag at io.com>
To: cctech at classiccmp.org
X-Priority: 3 (Normal)
> Date: Thu, 9 Jul 2009 12:00:48 -0400
> From: Ethan Dicks <ethan.dicks at gmail.com>
> I tried to look that up and found it easy to see that the IIfx needed
> something odd (I couldn't find specifics), so well done there. It
> would be interesting to get the details to see where Apple went off
> the rails from the SCSI spec.
IIRC, it's a matter of adding a capacitor and maybe a resistor to a
regular terminator. There's an Apple Technical Note or similar available
somewhere. I probably have a copy squirreled away on my hard drive at
home. And I think I remember that they use a somewhat higher value
capacitor (so add a smaller one in parallel on an existing terminator) and
a lower resistance (so again, add a resistor in parallel). But I could
Again, IIRC, the IIfx's SCSI was too noise sensitive. But I've also
heard/read that that was only true for the early production run and that
the later built machines did not need the funny terminator.
>> Then I would only need to find an AUI to RJ-45 doodad
>> which is skinny enough to fit into the recessed ports on the IIfx. I
>> have an AUI thingy now, but it's too fat to reach the db-15 connector
>> on the network card.
> Are you sure that's an AUI connection? I would expect a Mac of that
> vintage to have a DA-15 for video but not Ethernet.
Seconded. There were NuBus AUI ethernet cards, but much more common would
be a card with AUI and either or both of a BNC and RJ45. If the card
only has a DA-15 there's a very good chance that it is a video card. If
it has a big 'BT' labeled chip near the connector, it is almost certainly
a video card.
More information about the cctalk