From: hank@ducvax.auburn.edu
Newsgroups: comp.os.os2.misc
Subject: Re: Com3 using com.sys
Date: 28 Sep 92 01:33:01 GMT
Distribution: na
Organization: Auburn University, AL

In article <q4#p67g.parity@netcom.com>, parity@netcom.com (Parity Systems) writes:
> I have a mouse on com1 irq4 a 14,400 modem on com2 irq3 and a fax/modem
> on com3 irq4. The problem is with com 3 the modem can be configured for 
> the com port but not the IRQ.. When i've set com.sys to 3,3e8,4 it bombs.
> it also bombs as irq 2,5. Can I use there IRQ's? Do I have to change the 
> mouse IRQ? if I do, what IRQ's are available to use?

The board must have a setting for IRQ in order to change it--you cannot
simply "assign" it an IRQ.

You cannot use com1,IRQ4 and com3,IRQ4 at the same time. In fact, you may 
have to "fool" OS/2 just to get com3 installed as IRQ4 (see notes below).

There are two common problems with com3:
  1. OS/2 can't find it.
  2. One wants to use IRQ4 with com3 (and com1 is installed but will not
     be used).

You are not quite in either of these. You may get away with using the
com16[45]50.sys driver for com3 provided you don't try to use com1 at the
same time. I do this with OS/2 1.3 (I have a built-in com1 that cannot
be disabled). I do not know if com16[45]50.sys will give the com port to
a dos-box.

It seems that I have left the big question unanswered: Can com1,IRQ4 and
com3,IRQ4 be set up and used (as long as they are not used at the same time)?

Attached are some notes I've been collecting on com3 problems.

--darrel hankerson hank@ducvax.auburn.edu

> I set up my COM drivers in config.sys with the (3,3E8,4) statement, and
> the modem initializes -- after the _third boot_.  The modem will never 
> initialize after one or two hard boots, only after at least the third,
> sometimes longer.  Strange, because I have no trouble on the first boot
> with DOS 5.0...and my AMI BIOS says 3E8 is a valid address on the first 

Many have this kind of problem. Some "solutions"
 
1. The commga (2210?) drivers were reportedly better at finding ports.
Unfortunately, they had other problems which I've forgotten.

2. Some folks (like me) can "touch" their port, then ctrl-alt-del. Someone
suggested touching from dos (with procomm? echo > com3 ?), then re-boot and
OS/2 recognizes the port.

I used the com16[45]50.sys drivers (originally designed to bring com3 to OS/2
1.3). These work as my com driver in OS/2 (didn't test dos-boxes). I can
also remove these lines from my config.sys, put the usual lines back in, and
ctrl-alt-del. Everything works, until the next power off-on.


3. Some folks want to use IRQ4 with com3 and com1 (but not use both ports at
the same time). It has been reported that the "IRQ not available" message
can be avoided by giving OS/2 some other IRQ number for com1 (the post said 
to use the same IRQ as used by the mouse). NOTE: I am not saying that this
gives use of both ports com1 and com3.

Jon R Bryan (bryan@isrc.sandia.gov) writes (19-Jul-92):
First set them to unique interrupts using the appropriate
jumpers/switches.  I have my COM3 set to IRQ5 and COM4 set to IRQ2 (COM1
uses IRQ4 and COM2 uses IRQ3).  Then edit your CONFIG.SYS file and add
the following to both the COM.SYS and VCOM.SYS lines.  Here is how mine
look:
 
DEVICE=F:\OS2\COM.SYS (3,3E8,5) (4,238,9)
DEVICE=F:\OS2\MDOS\VCOM.SYS (3,3E8,5) (4,2E8,9)
 
The format is (x,yyy,z) where x=COMx, yyy=i/o port address, and z=IRQz.
You'll note that I set COM4 to IRQ9.  On AT-class machines that's where
IRQ2 is mapped.
 
You will probably get messages that say "COM3/4 not Installed.  Interrupt
Not Available" when you reboot.  What I do next is run Procomm+, where I
have defined the address and interrupt for COM3 and COM4, and "touch"
each port (I hook my modem to COM3 and COM4 in turn and send "AT<CR>").
Then I reboot and OS/2 recognizes the ports until the next time I power
down.  This is a bug I expect IBM to fix in the next release.
 
By the way, I also replaced all the 16450 UARTs in my machine with
NS16550AFN (equiv. PC16550CN) chips.  You should be able to find them
for about $10 (I paid $7, but I get a discount).  You'll get much better
performance.
-- 
Jon R. Bryan	(505) 844-2015	<=>	bryan@isrc.cs.sandia.gov
Sandia National Laboratories, Intelligent System Sensors and Controls
 

com16[45]50.sys can be found at ftp-os2.nmsu.edu in pub/os2/1.x/sysutils/, if
I recall correctly.


From: gershon@husc10.harvard.edu (Ethan Gershon)
Newsgroups: comp.os.os2.misc
Subject: Re: problems with modem/com port
Date: 6 Sep 92 03:28:42 GMT

JXL103@psuvm.psu.edu writes:

>...still somewhat new to OS/2....I currently have an Intel Satixfaxtion Modem
>/400, Pmcomm 1.10....I have my modem set to Com 3, (3e8, irq 5), and I can't
>get the pmcomm to work...I'm running the beta comm drivers (from COMMGA.zip).
>On my Boot manager setup, my modem works fine in DOS.....any suggestions?

I had similar problems getting my com3, 3E8, irq5 to work. Someone sent
me the following solution, which worked perfectly.  (note that I have
no idea *why* this works or what it does.)

>CD to the OS2 subdirectory.
>COPY COM.SYS to COM.OLD
>PATCH COM.SYS
>Select offset 7F2, where you should see 74 4A.
>Replace the two bytes with 90 90 (NOP's).
>Save the revised COM.SYS
>Reboot.

>I don't remember where I got this tip, but it works.

>Avoid the revised COM drivers.  They are unreliable.

>Another thing you can do is use a DOS application to talk to COM3 and
>then reboot.  That seems to initialize the UART so that on subsequent
>reboots the port will be recognized.

>--
>Jon R. Bryan    (505) 844-2015  <=>     bryan@isrc.sandia.gov
>Sandia National Laboratories, Intelligent System Sensors and Controls

                                                    --Ethan Gershon
                                                    gershon@husc.harvard.edu