Ken Hornstein <kenh@cmf.nrl.navy.mil> writes:

> There are some video cards that use the com3 I/O space, and when the
> com probe routine tries to probe for com3, the card gets in a mode
> where it doesn't display anything (I have one of these cards).

I think the issue is

com0	at isa? port 0x3f8 irq 4	# Standard PC serial ports
com1	at isa? port 0x2f8 irq 3
com2	at isa? port 0x3e8 irq 5
#com3	at isa? port 0x2e8 irq 9

vs

com*	at isa? port 0x3f8 irq 4	# Standard PC serial ports
com*	at isa? port 0x2f8 irq 3
com*	at isa? port 0x3e8 irq 5
#com*	at isa? port 0x2e8 irq 9

not

com*    at isa? port ? irq ? 

which would be hard to support.

I suppose one reason to use com0 instead of com* is to make sure these
ports are exactly that.

/Johan