Re: PC104 Serial Port Programming


"starman" <sdoan003@xxxxxxx> wrote in message
news:1131466253.534932.166080@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>I am working with a SBC1390 and I am attempting to write a program
> which will read and write data out of COM1, COM2, COM3, and COM4. I
> have COM3 and COM4 working as they should however I cannot get COM1 and
> COM2 to work for the life of me. I am writing the program in C and
> like I have said the code works just fine on my PC and for COM3 and
> COM4. I will say that COM1 and COM2 are independant of COM3 and COM4.
> Is there anyone out there who might be able to shed some light on this
> issue. Thanks
>

Look in the BIOS. You can't share an IRQ between ports. Your IRQs should
look something like this example from my project.

COM1, Port 3f8-3ff, IRQ 4
COM2, Port 2f8-2ff, IRQ 3
COM3, Port 3e8-3ef, IRQ 10
COM4, Port 2e8-2ef, IRQ 11

Peter


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