🚀 go-pugleaf

Serial Driver Problem

I hope this is the right place for this.  If not, please
let me know.

I'm trying to program the serial port to control some equipment.  I
can't seem to get it (i.e. the port) to generate interrupts (such as
the data received, or transmitter empty)

What am I doing wrong?

Here's what I've done so far (briefly, sort of).

1.      Replaced vector 0x0c with my interrupt service routine. I'm
pretty sure this right, because a  geninterrupt(0x0c) gets to my
routine.

2.      Set up the serial port to interrupt on everything but the modem
status change by writing 0x07 to the interrupt enable register.

3.      Set 8259 interrupt controller to enable interrupts from IRQ3
and IRQ4 with outp(0x21, inp(0x21) & 0xe7);

4.      End my interrupt service routine with outp(0x20, 0x20).

When I do a write followed by a read, I get the data I sent.  I've done
this using the loopback feature (set bit 4 of the modem control
register) and by wiring pins 2 & 3 together, so the connections are
right.  I've also done the above for the second serial port, I just
can't get the hardware to generate interrupts.

Any ideas.  I'll post (or email) code if it'll help me get an answer.
Please email or post any replies (but email is preferred).

Thanks for any help you can give me.  I'm really troubled by this.  I'm
sure I'm doing something dumb here.

Don