68kMLA Classic Interface

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Serial cable issues
Posted by: chu-oh on 2019-01-29 02:10:47 I've been trying to get my Plus to talk to my iMac via Z-term, a serial cable a gender changer and a usb to serial adapter. But I can't for the life of me get them to talk to each other, I've got matching settings on both, the Belkin adapter's TX signal lights up when I send a string from the iMac end and the link light flashes on the Belkin adapter when the Plus sends something - but nothing appears on either end. Midi works fine on the Plus's modem port fine so I don't think there's any issue with the Plus, I've also tried 2 different usb adapters with and without the gender changer and no luck. I tested continuity on the cable with a multimeter and this is the only pin that doesn't get a signal, does that mean it's faulty? I've got a few Arduino Nano's floating around so I could probably fashion something with them and a Mini DIN-8 connector, but I'm not sure what the difference between simple RX/TX and the Serial Pin out:
Posted by: Dog Cow on 2019-01-29 08:52:04 Probably your cable pinout is wrong. This article Mac RS232 Serial Connection has complete instructions on making a cable. Also, check out this pinout chart, which is also in that article.
Posted by: chu-oh on 2019-01-29 13:16:16 Weirdly enough it was old/new stock labled as a Mac Plus serial adapter. But I'll check with the multimeter if the pins match up. Otherwise I'll fashion a new one. Cheers.
Posted by: Dog Cow on 2019-01-29 13:49:31 Weirdly enough it was old/new stock labled as a Mac Plus serial adapter. That's fine and dandy, and you could use that cable to connect directly to another Mac. However, the problem is that Apple's pinout for RS232/422 is not industry-standard, and therefore almost certainly does not match the pinout on your USB-serial adapter.
Posted by: chu-oh on 2019-01-29 16:02:27 That's fine and dandy, and you could use that cable to connect directly to another Mac. However, the problem is that Apple's pinout for RS232/422 is not industry-standard, and therefore almost certainly does not match the pinout on your USB-serial adapter. Haha fair point! I'll try and wire up a new one and see how I go.
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