I want to control a "turtle" connected to my computer Mac or Windows via a USB device. Is there a way to detect the USB device and write to it from HyperNext?
Its possible to use USB input/output on Windows platform. However, on the Mac platform it was unreliable so disabled.
Project 34 - "USB Devices" has some basic USB monitoring of a device. You need to know the Product and Vendor number of the USB device.
Project 33 - "Lightstone" is a detailed USB project for monitoring heart rate.
Chapter 29 of the Language Reference has details on USB, including procedures/functions.