Int 17 Fn F0  - Northnet Jetstream Api - Installation Check                [P]

   AH = F0h
   DX = printer port (0-3)

Return: AX = 0001h Jetstream present
        else  non-Jetstream port

Note:  NorthNet Jetstream is a high-performance DMA-driven parallel card able
     to drive printers at up to 80000 characters per second