Geoport and Localtalk

Question

Level 1

4 points

Geoport and Localtalk

Hey all,

I have a Performa 200, and getting an old Mac II. I fear that the system software is bad on my Mac II. Both the Performa 200 and the Mac II have no geoports, but serial only.

I wanted to get a bridge machine, and thought maybe a Powerbook would be the best way to go. The models I am looking at have no serial ports, but geoports only.

Through the research I've done, I understand that Geoports are localtalk compatible. With a printer/serial cable, can I plug in my older mac serial port, directly into my "newer" mac's geoport and be able to network files across? I wasn't sure if Geoports could talk to Serial ports with the standard cabling.

-Pat

Performa 200-OTHER, Mac OS 8.6 or Earlier

Posted on May 9, 2013 7:01 AM

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Answer 1

⚠️

Top-ranking reply

JustSomeGuy

Level 3

606 points

May 9, 2013 10:37 AM in response to pfeinauer

You might have a bit of a challenging time finding the Geoport-to-serial cables - GeoPort used 9-pin min-DIN instead of Apple's usual 8:

http://pinouts.ru/SerialPorts/apple_geoport_pinout.shtml

http://lowendmac.com/roadapples/geoport.shtml

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Answer 2

pfeinauer Author

Level 1

4 points

May 9, 2013 5:19 PM in response to JustSomeGuy

Please see link below:

http://mysite.verizon.net/res1cymj/media/pm7500.pdf

The link is an Apple sales brochure for the powermac 7500. As far as I can tell, a newer G3 that I'm looking at, as well as the later powerbooks, and G3, only have Geoports.

On the left side of page 1, under the Communications and Multimedia section, point #2 states "Two high-speed serial ports compatible with GeoPort and LocalTalk cables". Are they referring to a localtalk cable as the 8pin din, and the geoport as the 9pin din?

Many other sites, I have found, state an 8 pin cable will plug directly into the 9pin connector, minus pin 9, which provides +5 volts. I'm assuming after this newly found research, I can localtalk directly an older Mac to a Geoport mac with just an 8pin to 8pin cable. Am I reading this correctly?

-Pat

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Answer 3

May 9, 2013 5:26 PM in response to pfeinauer

Ah, yes - that is how I'd read that. The ports must be pin-compatible so that a normal printer cable would plug into the GeoPort, and would simply not connect the +5v. I've never owned a GeoPort machine myself, so I don't have direct experience with it. But it makes sense. So I'd say the machine you're after will ultimately succeed in serving Localtalk to the Mac II.

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Answer 4

pfeinauer Author

Level 1

4 points

May 9, 2013 5:42 PM in response to pfeinauer

Yes! Now on to Mac shopping!

-Pat

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Geoport and Localtalk