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'[OT] Comm Port set ups'
1997\11\28@065457 by Mike Watson

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Hi,

I have a need to operate 3 comm ports on my pc, so bought a
standard card that has FDD, HDD, game, LPT and 2 COMs. I disabled
the FDD, HDD and game ports and configured the com ports to
3 and 4 using jumpers on the board.

Having installed the card, Win95 detected the new ports. All well
and good, but in use, com3 stops com1 working and com4 stops com2.

It must (surely) be possible to configure the system so that I can
use at least three of the ports at the same time.

Anyone help me out on this?


Thanks and regards,


Mike Watson

1997\11\28@070329 by Fredrik Strand

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Hi!

You should try to check for IRQ and Address conflicts between the com
ports.


Regards,

Fredrik Strand

1997\11\28@070742 by WF AUTOMACAO

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Mike Watson wrote:
>
> Hi,
>
> I have a need to operate 3 comm ports on my pc, so bought a
> standard card that has FDD, HDD, game, LPT and 2 COMs. I disabled
> the FDD, HDD and game ports and configured the com ports to
> 3 and 4 using jumpers on the board.
>
> Having installed the card, Win95 detected the new ports. All well
> and good, but in use, com3 stops com1 working and com4 stops com2.
>
> It must (surely) be possible to configure the system so that I can
> use at least three of the ports at the same time.
>
> Anyone help me out on this?
>
> Thanks and regards,
>
> Mike Watson

Are you using differents IRQ?

Miguel.

1997\11\28@072651 by Jacques Vrey

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{Quote hidden}

Hi there

A PC's COMM ports 1 & 3 use interrupt 4 and 2 & 4 use interrupt 3, as
a result, they interfere with eachother. I haven't tried this but
perhaps you could hard wire any other two (open) interrupts on your
new i/o. ie physically cut the IRQ 3 & 4 connectors on the card and
solder them to the other two new (open) edge connectors. I've don
this for other cards before (not comm). You'll need the pin-out's for
the ISA slot for that, unfortunately I don't have one with me now.

If this isn't too clear, e-mail me privately and I'll explain with
more detail.

Regards



Jacques Vrey
Iscor Steel Profile Products
Internal Post Point 74
PO Box 2
Newcastle
2940
South Africa
Tel: +27 (0)3431 48759
Fax: +27 (0)3431 48001
spam_OUTjvreyTakeThisOuTspamit.new.iscorltd.co.za
The views expressed above are not necessarily those of Iscor Limited.

1997\11\28@074321 by Andy Kunz

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>Having installed the card, Win95 detected the new ports. All well
>and good, but in use, com3 stops com1 working and com4 stops com2.
>
>It must (surely) be possible to configure the system so that I can
>use at least three of the ports at the same time.

You most likely have interrupt conflicts.

Right-click on My Computer, go to Properties.  Click on the Device Mangler
(oops, Device Manager) tab.  Click the "+" beside Ports (COM & LPT).  In
turn, double click each of the ports and look at the Resources it uses.

My guess is that you see multiple comm ports sharing and IRQ.  This
probably will report as "No Conflicts" in the box at the bottom, even
though they are doubled-up.

My suggestion is to put each port on a unique IRQ.  I prefer to leave COM1
on 4 and COM2 on 3 to retain DOS compatibility with these ports (COM2 is my
mouse), then put COM3 on IRQ 7 (usually assigned to LPT1 but actually not
used) and COM4 on IRQ 5 (normally LPT2 or mouse).  This is, actually, how
my system is configured.  Must work - I sent this e-mail to you!

If, like me, you have your system maxed out with IDE controllers, sound
cards, NIC, etc then it might not be possible to have everything unique.
In that case, set priorities for yourself.  You might have to disable some
of the sound card, or you can still double-up some of the COM IRQs.

NOTE:  If you are using an external drive (Zip, parallel-to-SCSI, etc.) you
probably need to use the LPT IRQ as it was originally assigned.  In that
case, you might have to go to the second interrupt controller (IRQ's 8 and
above) for your comm ports.  If you have a card that had an IDE controller
on it but won't give you IRQ 10 (etc) for the comm ports, you can always
configure jumpers to use IRQ 5 or 7 or whatever and then cut & jumper it to
IRQ 10 or 11 or whatever.  I did that already also, and it does work.  If
you need the edge connector pinout, let me know PRIVATE and I'll send it
when I can.

Andy

==================================================================
Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
         Hardware & Software for Industry & R/C Hobbies
       "Go fast, turn right, and keep the wet side down!"
==================================================================

1997\11\28@075556 by bejones

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This is a well known feature of Windows (3.1 and 95). The default
seting is for COM1 and COM3 to share the same IRQ (4) and COM2 and
COM4 to share IRQ3.

You need to check your system settings on WIN95 to find free
IRQs (I think my home machine which as 4 COM ports working AOK (and 3
Parallel ports) uses IRQ10 and IRQ12 for COM3 & 4) and set your I/O
card to use these IRQs  for COM3 and 4 (either by software
configuration  or jumpers). Reinstalling the card Win95 may recognise
and use the new IRQs or you may need to fiddle with the system config
a bit.

Brian
Brian Jones
Java Technology Centre
IBM Hursley

1997\11\28@083024 by Keith Dowsett

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At 11:44 AM 11/28/97 GMT, you wrote:
{Quote hidden}

You will probably find that com3 shares an IRQ (interrupt request) with
com1 and com4 with com 2. This is fairly standard practice, so I don't see
why windows can't handle it. (OK, so the word cr*p springs to mind.) You
can check this in the Control Panel /system / ports/ COMn/ resources  which
shows the IRQ for each port.

You may have to change the IRQs to aviod these conflicts. If the serial
board won't allow you to configure it's interrupts, try your motherboard
setup. (My ASUS one has a menu for this.)

Hope this is some help.

Keith
Keith Dowsett      "Constants aren't, variables won't"

   E-mail:     .....kdowsettKILLspamspam@spam@rpms.ac.uk
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Snail mail:     MRC Cyclotron Unit, Hammersmith Hospital, London W12 0NN
      Fax:     +44-181-383-2029

1997\11\28@093701 by mike

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In message  <30344DE1777spamKILLspamiet-1.iet.hist.no> .....PICLISTKILLspamspam.....MITVMA.MIT.EDU writes:
> Hi!
>
> You should try to check for IRQ and Address conflicts between the com
> ports.
>
>
OK. What do you recommend I set them to?

Regards,

Mike

1997\11\28@100000 by Ian Cameron

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> I have a need to operate 3 comm ports on my pc, so bought a
> standard card that has FDD, HDD, game, LPT and 2 COMs. I disabled
> the FDD, HDD and game ports and configured the com ports to
> 3 and 4 using jumpers on the board.

This is a 16 bit ISA card then I guess.

> Having installed the card, Win95 detected the new ports. All well
> and good, but in use, com3 stops com1 working and com4 stops com2.

Most of these multi I/O cards only allow you to select interrupts 3
and 4 for the serial ports.  This in effect only allows you to swap
which interrupt you use for each port.  Sharing interrupts for COM1/3
or COM2/4 (as typically configured) is fine until you want to use one
or both of these pairs of ports together.  If you want to do that,
you will need separate interrupts.

> It must (surely) be possible to configure the system so that I can
> use at least three of the ports at the same time.

Well, if you can select for example interrupts 10 and 11 for COM's 3
and 4 respectively, then that is all you need to do.  If you can't do
that, the only other option is to modify the card.

I have done this on 8 bit cards, all you need is a couple of bits of
wire and some Veroboard.  I suspect you may run into a bit of a
problem modifying your card if it is 16 bit.  Because it is common
practice to only put plated tracks in place on pins which are
actually used by the card, you may find that there aren't any for the
pins where other spare interrupts are located.  This will make it a
bit more of a pain to do the modification.  You can get around this
by plugging your Veroboard into another 16 bit slot, if you have one
spare, or behind an existing 8 bit card which is occupying a 16 bit
slot.

In the case of the 8 bit cards, all you do is cut the tracks to the
pins for interrupts 3 and 4, and then link them to the tracks on a
bit of Veroboard which you plug in behind the the card in a 16 bit
slot.

If you want/need to do this, I can post a pin out of the 16 bit ISA
connector if you don't have any information on it already.

Hope this helps.

Cheers, Ian.

1997\11\28@103913 by Christoph Klein

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Mike Watson wrote:
>
> Hi,
>
> I have a need to operate 3 comm ports on my pc, so bought a
> standard card that has FDD, HDD, game, LPT and 2 COMs. I disabled
> the FDD, HDD and game ports and configured the com ports to
> 3 and 4 using jumpers on the board.
>
> Having installed the card, Win95 detected the new ports. All well
> and good, but in use, com3 stops com1 working and com4 stops com2.
>

welcome to windows ;)

i never managed to use three (let alone 4) com ports AT THE SAME time.
in addition i don't think it works at all with regular hardware. there
are special i/o boards though that are supposed to provide you with
more ( f.e. 8 ) ports but the price inhibited my interest ...

switch to lpt or use linux ;)

christoph

1997\11\28@111818 by Matt Bonner

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Mike Watson wrote:
> I have a need to operate 3 comm ports on my pc, so bought a
> standard card that has FDD, HDD, game, LPT and 2 COMs. I disabled
> the FDD, HDD and game ports and configured the com ports to
> 3 and 4 using jumpers on the board.
>
> Having installed the card, Win95 detected the new ports. All well
> and good, but in use, com3 stops com1 working and com4 stops com2.
>
> It must (surely) be possible to configure the system so that I can
> use at least three of the ports at the same time.

As you're probably aware, Com1 and Com3 share the same interrupt, as do
Com2 and Com4.  I've always found that my internal modem works well when
sharing the irq with my mouse.  My configuration is:
 Mouse: Com2
 Modem: Com4
 Other: Com1
In my case, "other" is a switch box to switch between my PIC-Start plus
and my datalogger.

Another problem could be that Win95 assigns interrupts, so one of your
Com ports might be mapped to IRQ5 (for example).

To check out your Win95 settings, do the following:
1. Right click on "My Computer"
2. select "properties"
3. select "Device Manager" tab
4. open "Ports"
5. select a port, push "properties"
6. select "Resource" tab.
7. repeat 5 and 6 for all ports
For a "standard" (pre-Win95) setting, you should see
Com1: I/O 03F8-03FF Irq 04
Com2:     02F8-02FF     03
Com3:     03E8-03EF     04
Com4:     02E8-02FF     03
If you don't have the above, unclick "Use automatic settings" on the
rsource tab and set them to the above.  This _should_ be safe because it
is unlikely that Win95 selected any of these settings for other devices.

::Matt

1997\11\28@122737 by Andrew Warren

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Mike Watson <EraseMEPICLISTspam_OUTspamTakeThisOuTMITVMA.MIT.EDU> wrote:

> I have a need to operate 3 comm ports on my pc .... but in use,
> com3 stops com1 working and com4 stops com2.
>
> It must (surely) be possible to configure the system so that I can
> use at least three of the ports at the same time.

Mike:

By default, COM1 and COM3 use IRQ4, and COM2 and COM4 use IRQ3.

To use three ports simultaneously, you need to assign each port a
unique IRQ... The most-common arrangement is COM1 = IRQ4, COM2 =
IRQ3, COM3 = IRQ5.

Of course, IRQ5 is the default interrupt for the second LPT port, so
if you have two printers, you'll need to assign COM3 to some OTHER
interrupt... It can get complicated, although the difficulty can
sometimes be eased by using a serial card that supports IRQ10-15.

-Andy

=== Andrew Warren - fastfwdspamspam_OUTix.netcom.com
=== Fast Forward Engineering - Vista, California
=== http://www.geocities.com/SiliconValley/2499

1997\11\28@130237 by Brian C. Lane

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Hash: SHA1

On Fri, 28 Nov 1997, Mike Watson wrote:

> Hi,
>
> Having installed the card, Win95 detected the new ports. All well
> and good, but in use, com3 stops com1 working and com4 stops com2.

 This is definatly a IRQ conflict problem. COM1 and COM2 are normally at
IRQ3 and 4, so you need to reconfigure your card to use different IRQs for
COM3 and 4. Go in the the Windoze 95 system menu and look at the
hardware's IRQ usage. Pick 2 that your new card can support (usually they
are something like 5, 7, 9, or 11) and switch to them.

 4 ports are really great for development work. I have an ICE on one
port, a modem on another, another talking to the device being emulated and
another port monitoring a seperate serial bus.

 One big problem with win95 is that it doesn't like to have the mouse on
anything but COM1. I have some DOS serial code that only supports COM1 or
COM2, so I have a hard time running win95 at the same time <G>.

 Brian

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1997\11\28@145216 by Wim E. van Bemmel

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Hello Mike, (that's the one who needs an answer)

You installed the card and let Windows figure out how to install it.
The problem as I see it is in the interrupt handlers of the device drivers. I
know little of Win95 device drivers (still), but a lot more about how
interrupts are handled in a 80x86 system.
Sharing interrupts between more devices is well possible, but the drivers have
to be designed to do so. Most drivers just take over the interrupt vector
(modify it to point to their own interrupt service routine) and after handling
that do an IRET instruction, clean up the Interrupt controller, and that's it.
Mostly this is exactly what you want! This makes it possible to just install a
driver that interfaces to the name COM1: and magically the pre-installed one
is gone.. Drivers are designed (they have to) be chained. The last one
installed to that device name does the job, the others are bypassed.
Interrupts are not chained automagically. Sometimes however, one wants to
share the interrupt with an earlier installed device (= devicedriver). This is
your case.
Sharing interrupts means that you (beiing the driver) detect if the interrupt
was generated by your device, if so handle it, and pass the interrupt to the
previously installed handler. That is a lot more complicated.... especially
the control of the Interrupt controller.

What is good advice for you ?
I suspect the win95 drivers alltogether. They are ment for average users, not
for people like you who want to install more than 2 COM port driven devices.
Try to find drivers that are capable of sharing interrupts 3 and 4 between
ports
COM: 1,2,3,4. Of course you can write them yourself.
I did it for MSDOS and WIN311 using Blaise Computing Inc.'s excellent Asynch
Manager. That was some years ago (1993), it worked  under Win3.11 that still
supported MSDOS drivers, but they may have Win95 compatible products by now.
In between you could experiment with the sequence in which the drivers are
loaded... as I explained, a good driver does not monopolize an interrupt, but
shares it through chaining. This has to do with the way the silicon is
arranged on the motherboard, not with the operating system. The bad boy must
go first...
In Win95 - I am no expert still - throw away all your COM ports and reinstall
them one by one, try and keep record. On paper. One gets distracted by
repeated failed experiments.....

Good luck Mike !

To Miguel:

Mike told us he did.

WF AUTOMACAO wrote:

{Quote hidden}

--
Regards,

Wim
------------------------------------------------
 Wim van Bemmel, Singel 213 3311 KR Dordrecht
 Netherlands
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 ... Life is about Interfacing .....
------------------------------------------------

1997\11\28@160750 by Herbert Graf

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-----Original Message-----
From: Mike Watson <RemoveMEmikeTakeThisOuTspamD-M-G.DEMON.CO.UK>
To: spamBeGonePICLISTspamBeGonespamMITVMA.MIT.EDU <TakeThisOuTPICLISTEraseMEspamspam_OUTMITVMA.MIT.EDU>
Date: Friday, November 28, 1997 06:56
Subject: [OT] Comm Port set ups


{Quote hidden}

   Standard IRQ problem, you have to change the IRQs of two of the ports,
both com1 and 3 use by default IRQ4 and Com 2 & 4 use IRQ 3, you have to
change two of the ports to different IRQs in order to use them all at the
same time. Check your card to see if it has jumpers for IRQ setting. TTYL

1997\11\29@143146 by Andy Kunz

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>Of course, IRQ5 is the default interrupt for the second LPT port, so
>if you have two printers, you'll need to assign COM3 to some OTHER
>interrupt... It can get complicated, although the difficulty can
>sometimes be eased by using a serial card that supports IRQ10-15.

Unless you are using some OS more modern than a Redmond product, IRQ's are
not used for the LPT ports when operating as printers.  If you go to the
more advanced modes, or use them for laplink/SCSI adapters, then they are
used.

Andy


==================================================================
Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
         Hardware & Software for Industry & R/C Hobbies
       "Go fast, turn right, and keep the wet side down!"
==================================================================

1997\11\30@121403 by Larry G. Nelson Sr.

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The problem is with the IRQs. Com 1 shares with Com 3 and Com 2 shares with
Com 4. If you have drivers that do not need the IRQ or if you can change
them to other unused IRQs this can work. I did a project a while back under
Linux that had 8 com ports that could share IRQs without problems but a
special com driver was required.


At 11:44 AM 11/28/97 GMT, you wrote:
{Quote hidden}

Larry G. Nelson Sr.
RemoveMEL.NelsonspamTakeThisOuTieee.org
http://www.ultranet.com/~nr

1997\11\30@194639 by Ross McKenzie

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At 16:37 28/11/97 +0100, Christoph wrote:
>Mike Watson wrote:
>>
>> Hi,
>>
>> I have a need to operate 3 comm ports on my pc, so bought a
>> standard card that has FDD, HDD, game, LPT and 2 COMs. I disabled
>> the FDD, HDD and game ports and configured the com ports to
>> 3 and 4 using jumpers on the board.
>>
>> Having installed the card, Win95 detected the new ports. All well
>> and good, but in use, com3 stops com1 working and com4 stops com2.
>>
>
>welcome to windows ;)
>
>i never managed to use three (let alone 4) com ports AT THE SAME time.
>in addition i don't think it works at all with regular hardware.

Rest assured, you can have 4 COM ports operating "with regular hardware". Of
course it depends what you call regular <g>. I've designed and had operating
a weather monitoring system that used 3 RS232 lines to connect to the
outlying sensors and the 4th com port connected to the modem to ring the
operators at home to tell'em to come to make artifical snow when the
conditions are right. I used 2 vanilla flavoured com port boards, disabled
one port so the modem would work and used the remaining 3 sharing IRQs where
needed.

However, Win95 is definitely a horse of a different colour....

Ross McKenzie
Melbourne Australia

>there are special i/o boards though that are supposed to provide you with
>more ( f.e. 8 ) ports but the price inhibited my interest ...
>
>switch to lpt or use linux ;)
>
>christoph
>


'[OT] Comm Port set ups'
1997\12\01@014235 by Dean
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Here maybe another option, if you have a newer computer, especially
the later Pentiums, they sometimes have a PS\2 mouse port, sometimes
when the computers are assembled the on board PS\2 cable and socket
is left out, and you just use the normal serial mouse (DB9 PIN Socket)
If you are the first owner you might have a cable and socket laying
around for it, sometimes not. A PS\2 mouse port has a MINI DIN plug. My
PS\2 mouse runs off IRQ 12 (typical I think) leaving both IRQs 3 and
4 available.

Dean.

(-;     "Beauty is in the eye of the beer holder..."

;-)

{Quote hidden}

1997\12\02@081202 by mike

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In message  <9711281453.AA16046EraseMEspam.....damson.open.ac.uk> EraseMEPICLISTspamMITVMA.MIT.EDU
writes:
> > I have a need to operate 3 comm ports on my pc, so bought a
> > standard card that has FDD, HDD, game, LPT and 2 COMs. I disabled
> > the FDD, HDD and game ports and configured the com ports to
> > 3 and 4 using jumpers on the board.
>

Hi,

Thanks to everyone who answer my plea for help. I've got it sorted
now.

Regards,

Mike

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