Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!unhd!rg
From: rg@uunet!unhd (Roger Gonzalez )
Newsgroups: comp.sys.ibm.pc.misc
Subject: MID (Multiple line interrupt driver) and compatibility
Message-ID: <1990Oct16.162222.8468@uunet!unhd>
Date: 16 Oct 90 16:22:22 GMT
Reply-To: rg@unhd.UUCP (Roger Gonzalez )
Distribution: comp
Organization: Marine Systems Engineering Lab
Lines: 35

I'm using MID to drive com3-com10 on an 8 line serial board.  I already
have com1 and com2 on the motherboard.  Although DOS 3.3 and 4.1 both
can apparantly see that there is "something" at the proper address, I have
been unable to access the ports using Procomm or the latest Kermit.  I have
set the addresses on the board to
com3  210
com4  218
com5  3e8
com6  2e8
com7  3e0
com8  2e0
com9  220
com10 228
all on IRQ 5.  I left com1 and com2 at the appropriate addresses and IRQ's.
I noticed that on bootup the display showed the four serial ports as
3f8,2f8,3e8,2e8
Which map on my board to com1 com2 com5 and com6.  Unfortunately, I can't
just use 3e8 and 2e8 for com3 and com4, because of compatibility reasons with
some frequently used software :-(

MID completely replaces Int 14, and thus appears to be handling com1 and
com2 as well.  A test program is able to access the extra 8 ports fine, but
no off-the-shelf utilities can use them.  Am I doomed?  Are my programs
undercutting Int 14 and going straight to the metal for speed?  Are DOS's
ideas of com3 and com4 overriding my custom handler?

HELP!

-Roger

-- 
"The question of whether a computer can think is no more interesting
 than the question of whether a submarine can swim" - Edsgar W. Dijkstra 
rg@unhd.unh.edu               |  UNH Marine Systems Engineering Laboratory
r_gonzalez@unhh.bitnet        |  Durham, NH  03824-3525