I use a variety of devices which are easily managed using a built in serial interface, including Juniper/Netscreen switches and firewalls, Soekris computers, PC Engines computers, and so on. My working computers are a Macbook 2,1 running OS X 10.6.8 which dual boots into OpenBSD, a newer Macbook Air 7,2 running OS X 10.15, and a Dell Vostro running OpenBSD. I have tried a number of USB-serial adapters; in the recent past, I was using a Keyspan (which has a Prolific chip) which required installation of drivers. Now, I have settled on a Startech ICUSB2321F (which uses a FTDI chip). This is the best of many as it works out of the box without requiring drivers or additional software.
For the Dell or the Macbook 2,1, both running OpenBSD, simply plug it in and, in your shell,
cu -l cuaU0 -s 19200
or whatever speed is the appliance default.
I you boot into OS X 10.6.8, open Terminal and the command is
cu -l ttyu0 -s 115200
For 10.15, it's a bit different. The command is
cu -l /dev/cu.usbserial-###### -s 115200
where ###### is the serial number of the device. The device is easily found by
ls /dev | grep cu
Super easy and works a treat.
Posted by Gordon, No Hair Blog, May 30, 2020
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