[comp.sys.ibm.pc] COM3,COM4

kthomas@yale-zoo-suned..arpa (Kevin Thomas) (12/10/87)

All of my technical documentation on the pc and at predated com3 and
com4, but I now need to make my software work with them.

Does anybody know the interrupt number and (base) port address for
com3 and com4 on the pc/xt/at ?

Thanks in advance,
kmt

wales@CS.UCLA.EDU (12/18/87)

In article <20049@yale-celray.yale.UUCP>
    {backbone}!esquire!kthomas!kthomas writes:

>Does anybody know the interrupt number and (base) port address for
>com3 and com4 on the pc/xt/at ?

According to Appendix D of my ProComm 2.4.2 manual:

    COM3 has a base port address of 3E8h and interrupts at IRQ4.
    COM4 has a base port address of 2E8h and interrupts at IRQ3.

-- Rich Wales // UCLA Computer Science Department // +1 (213) 825-5683
	3531 Boelter Hall // Los Angeles, California 90024-1596 // USA
	wales@CS.UCLA.EDU           ...!(ucbvax,rutgers)!ucla-cs!wales
"Sir, there is a multilegged creature crawling on your shoulder."