Hello! Are AAUIs using the same serial communications model that the Mac used for all of its technology? As I recall it used the RS-422 methods for such functions as the GeoPort and even talking to printers.
I have found our original discussion on the subject, however Google Groups consider it to be a closed thread even though they have an archive for it.
AAUI is just like AUI, except with a 5V power supply and a different connector. As far as I know, Apple didn't want to put in power supplied big enough to run AUI.
The AAUI to AUI adapter is line powered.
-- glen
Hello! I understand that much. I was asking about the connector between the computer and the AAUI. I've found documentation both Apple written and from groups of Mac enthusiasts to explain what the pins and why, but nothing was stated about how the DI-A and the DI-B and CI-A, and the CI-B and then the DO-A and the DO-B are wired to. Or what is carried there. I believe they are indeed RS-422 connected pairs but I don't have a Mac Quadra (5 model numbers and styles) or a Mac Centris (2 model numbers and styles) to study before continuing with this further. I can state that I've met a Quadra before, but that was a long time ago. And in an different life. (The referenced location was
You could also find any first generation PowerPC computers. 71xx, 81xx,
91xx, etc... Plus I think second gen ones. Have you checked out the apple KB? Maybe the developer KB. The developer program has a free sign up for things like the KB. And you might find it in the user KB.
The response was quite clear: "AAUI is just like AUI ..."
The signals are AUI signals, NOT RS-422. There are three signaling pairs, Data In (DI), Data Out (DO), and Collision In (CI). They have the same characteristics as in a 12V-powered AUI. Apple only changed the power (to 5V), and the connector (to prevent accidentally plugging a 5V AAUI-powered device into a 12V AUI-powering device).
-- Rich Seifert Networks and Communications Consulting 21885 Bear Creek Way (408) 395-5700 Los Gatos, CA 95033 (408) 228-0803 FAX
Send replies to: usenet at richseifert dot com
And, as far as I know, you can't pull enough current to run a 5V to 12V converter. The Apple AAUI to AUI adapter was line powered.
If you want to run an AAUI transceiver off an AUI port, a 7805 regulator would probably do it.
The pinouts are in "Inside Appletalk, 2nd edition".
-- glen
Hello! I agree Rich, that was my typical stubborness surfacing. And given that Amazon reccomends two books of yours when purchasing the Spurgeon book on Ethernet, then I am entitedl to agree.
Glen I think I've got a PDF copy of that book someplace. I never did find in it an actual explanation for the strange configuration of pinouts but at least it makes some kind of sense.
More later gentlemen.
Hello! Minor spelling error in:
Spurgeon book on Ethernet, then I am entitedl to agree. ^^^^^^^^^ That should be "entitled". Other statements are still correct.
-- Gregg gregg dot drwho8 atsign gmail dot com
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