Found this in my archives from one of the batch buys.
SupraDrivers(02B).ATR 90.02KB 20 downloads
Includes R-Verter handlers for the Supra 300AT and 1200AT Modems. These incorporate full flow control using the I/O pins on Joystick Port #1 including the Trigger Input Line...
Edited by AtariGeezer, Wed Feb 13, 2019 3:35 PM.