INT 17 - NorthNet Jetstream API - INSTALLATION CHECK
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


17F0 - NorthNet Jetstream API - INSTALLATION CHECK