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Document ID: LWIK-3T4JQY

TP General - Guidelines on how to configure COM ports

Applicable to: World-Wide

This document contains guidelines for installing COM Devices.

Each device that uses a COM port must have its own unique resources. Here are the defaults:

Standard COM Port Resources:

COM	IRQ	I/O
1	4	03F8
2	3	02F8
3	4	03E8
4	3	03E8

You will notice that Com1/Com3 and Com2/Com4 have something in common - the interrupt. This will cause a conflict if you were to try and get 3 COM ports enabled at the same time using the above resources. You can however assign an available IRQ to COM3 if needed.

Keep in mind that some devices will ONLY accept default resources (this may limit you to only 2 COM ports at one time).

Some devices require a special utility, to modify their settings. Such as the BIOS on ThinkPads for Infrared and serial ports. These can be controlled by either PS2 commands or the appropriate version of utilities. (TP 701 configuration changes can be made by using Fn+F1 and paging down to the user port settings.) If the device you wish to configure has a unique or manufacturer supplied utility to configure it, it is preferred that you use that to configure the device.

To check/edit the resources, choose the Operating System you want to check.

Windows 3.1x:
1. Double click on the Main group icon
2. Double click on the Control Panel group icon
3. Double click on Ports icon
4. Double click on the port you want to check/edit
5. You can check/edit the IRQ/IO under the Advanced button

Windows 95/98:
1. Highlight My Computer
2. Right Click and Click on Properties
3. Click on Device Manager
4. Go down to the Ports COM and LPT section
5. Double click on the port you want to check/edit
6. Go to the Resource Tab to check/edit
7. Uncheck use automatic settings. (This will prevent Windows 95 Plug and Play from configuring the device.)
8. Select whichever resource you want to change, then click on change settings.
(If the device can not use non-standard settings, windows will usually tell you the settings can not be changed. If this happens then you should try to configure one of the other devices.)
9. Click on OK to exit.

Note: A good rule of thumb to observe is to let Windows 95 configure the first two devices that will be using standard resources, and then manually configure the third.

OS/2 Warp:
1. Double click on OS/2 System icon
2. Double click on Command Prompts icon
3. Double click on OS/2 Window
4. Type e config.sys and press enter
5. Look down the file until you get to the com.sys line for example: DEVICE=C:\OS2\BOOT\COM.SYS
6. Change accordingly For example if you want COM3 to use IRQ9 and I/O 03E8 then modify as follows: DEVICE=C:\OS2\BOOT\COM.SYS (COM3,03E8,9)
(This is just an example. You will need to check and see which resources your serial device supports and make the appropriate changes.)

If the application you are using with your serial device has a driver installed in the Config.sys file for OS/2 you may need to make changes to them. For example, if Faxworks in OS/2 is using a non-default COM port make sure the Faxworks driver (FMD.SYS) is looking for the same non default COM settings. For example:

DEVICE=C:\FAXWOS2\FMD.SYS L (COM3,03E8,9)

You will want to refer to the User's Guide for your particular application to see if any changes are necessary.

Note: No matter which operating system you are in, if you are making changes to resources for a device on the ThinkPad (serial port, IR, or internal modem), you need to make these changes through the configuration utility for your particular ThinkPad. Refer to your User's Guide for instructions for your particular ThinkPad.

	Search Keywords
	Hint Category	Communications
	Date Created	31-03-98
	Last Updated	06-04-99
	Revision Date	06-04-2000
	Brand	IBM ThinkPad
	Product Family	ThinkPad 310, ThinkPad 315, ThinkPad 360, ThinkPad 365X/XD, ThinkPad 365C/CS, ThinkPad 365CD/CSD, ThinkPad 365E/ED, ThinkPad 380, ThinkPad 380D, ThinkPad 380E, ThinkPad 380ED, ThinkPad 380XD, ThinkPad 380Z, ThinkPad 385D, ThinkPad 385E, ThinkPad 385ED, ThinkPad 385XD, ThinkPad 390, ThinkPad 390E, ThinkPad 560, ThinkPad 560E, ThinkPad 560X, ThinkPad 560Z, ThinkPad 600, ThinkPad 600E, ThinkPad 701, ThinkPad 750, ThinkPad 755C/CS, ThinkPad 755CE/CSE, ThinkPad 755CX, ThinkPad 755CV, ThinkPad 755CD, ThinkPad 755CDV, ThinkPad 760C, ThinkPad 760E, ThinkPad 760CD, ThinkPad 760L/LD, ThinkPad 760ED, ThinkPad 760XD, ThinkPad 760EL/ELD, ThinkPad 760XL, ThinkPad 765L, ThinkPad 765D, ThinkPad 770, ThinkPad 770E/ED, ThinkPad 770X, ThinkPad 770Z, ThinkPad i Series 1400, ThinkPad i Series 172x
	Machine Type	2600, 2620, 2625, 2635, 2636, 2626, 2640, 2641, 2645, 2646, 2630, 9545, 9546, 9547, 9548, 9549, 9544, 2611, 2627
	Model	Various
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