Hi,

IIRC LPT1 was at 0x378 at IRQ 7, LPT2 at 0x278 at IRQ 5, and 
LPT3 at 0x3BC at IRQ 7. 

IIRC it works something like this: if 3BC is there and no 378 it is 
treated as LPT1, if 378 is present it will be LPT3. But I might be 
totally wrong. 

I have one PC with onboard LPT and MGA that runs NetBSD (but 
there is no printer attached it works as a firewall machine).

And one of my customers has  a printserver with 3LPTs and 3 high 
speed dot matrix printers attached (DFX5000 ?). There is no 
network interface for these printers available and the data they have 
to spool can be rather large, so a "small" print server is out of 
question. I do not know what OS is used (netware 312 or 
something), it was just to demonstrate some of such machines do 
exist in the wild.

mike

On 26 Jun 2001, at 20:39, Greg A. Woods wrote:
> Oh, of course -- even with the cut&paste I failed to clue in on the
> missing 'irq' specifications!  ;-)
> 
> So, why doesn't it work even in polled mode?
> 
> (I wonder why IBM default it to 0x3BC too -- that's supposedly the
> port that would be on a really old monochrome adapter)
> 
> It's also very curious to me why lpt2 isn't defaulted to IRQ-7 in
> GENERIC too.  It's probably almost impossible these days to find a
> machine on which NetBSD will boot and which has both normal parallel
> ports _and_ a monochrome adapter.  Are machines with three parallel
> ports any more common?
> 
> In fact in reading my copy of the "Hardware Bible" I find it curious
> that the GENERIC kernel doesn't follow the same search rules as the
> BIOS (i.e. search at 0x3BC first).  Does GENERIC really need to have
> more than one "lpt" device?  Why not just have:
> 
>  lpt0	at isa? port 0x3bc irq 7	# monochrome parallel port
>  lpt0	at isa? port 0x378 irq 7	# standard PC parallel ports
>  #lpt1	at isa? port 0x278		# 2nd port, usually at IRQ 5
>