Specifications

Chapter 2 Hardware Installation 15
Independent IRQ Mode (JP1-JP4)
In this mode, each of the four ports can have IRQ channels set
individually. For each port, select an IRQ which is not already in use
by another card in the system. The map of jumpers and ports is
shown below.
Port 1 à JP1
Port 2 à JP2
Port 3 à JP3
Port 4 à JP4
Share IRQ Mode (JP1)
Select an IRQ which is not already in use by another card in the
system. If you are installing more than one PCL-849, set them to
different IRQ numbers. Jumper Bank JP1 controls the card IRQ.
Simply place the jumper on the required interrupt level as shown in
the following figure.
Interrupt Status Register Setup (S1, Vector
address)
This feature on the PCL-849 is utilized in the enhanced mode only.
When data arrives at one of the four ports, it will generate an interrupt
in the interrupt register. The PC software can read this, and identify
immediately which port generated the interrupt. This saves time, and
makes programming easier. When a data bit of the interrupt status
register is set to 0, the corresponding channel is selected to generate
an interrupt. If the bit is 1, then no interrupt is generated. DIP switch
S1 controls the card's interrupt status register, as shown in the follow-
ing figure and table.