Classic mac fun (and some questions)

[trag at io.com]

>       
     (continued...again...)
From: "Jeff Walther" <trag at io.com>
To: cctech at classiccmp.org
User-Agent: SquirrelMail/1.4.17
MIME-Version: 1.0
Content-Type: text/plain;charset=iso-8859-1
Content-Transfer-Encoding: 8bit
X-Priority: 3 (Normal)
Importance: 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
be misremembering.

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.
>
> http://lowendmac.com/ii/macintosh-iifx.html
>
> 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.

Jeff Walther