🚀 go-pugleaf

All I can tell you is that both the 7550 plotter and the HP Lasetjet II
have standard RS232 ports, and will hook up to ANY RS232 standard serial
device as terminals (DTE). To translate this into English, you only need
3 wires. Pin 2 is the output from the printer/plotter, pin 3 is its input,
and pin 7 is ground. They use Xon/Xoff handshaking. Just wire the Mac's
serial output to pin 3, the Mac's serial input to pin 2, and ground to
pin 7. If the Mac in question doesn't have a simple serial port, you
are SOL. Unless you can get a black box to convert the Mac's output
to standard serial.

Good luck.