Here are some suggestions on how to output from the serial ports using
Pascal.
Even though the serial ports are not devices for file storage, they must be
specified with a dummy file name. The Lisa handles all I/O devices this way.
(See the Pascal Operating System Manual.)
reset (f, '-rs232a-xyz') where xyz is the dummy name
If you're writing a program to talk to some other type of device, such as a
card reader or test equipment, review Chapter 2 in the System Software
Manual, particularly the section named Device_Control. These procedures
describe how to configure the drivers for either port in order to allow
communication with other devices.