Q123992: Basic Configurations for COM Ports in Windows 95
Article: Q123992
Product(s): Microsoft Windows 95.x Retail Product
Version(s):
Operating System(s):
Keyword(s): kbhw kbHardware
Last Modified: 24-JUL-2001
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The information in this article applies to:
- Microsoft Windows 95
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SUMMARY
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Windows 95 includes a set of "Basic Configurations" for communications (COM)
ports. These configuration options make it easier for you to avoid hardware
conflicts by letting you easily change the settings a COM port uses.
These Basic Configurations provide the following:
- A default configuration for each COM port. You cannot change this default
setting.
- Additional configurations for each port that lets you edit the IRQ setting.
These configurations do not let you change I/O addresses.
- Additional configurations for each port that lets you edit both the IRQ and
the I/O range.
MORE INFORMATION
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Basic Configurations are determined by the following table:
Basic
Configuration IRQ Setting Editable? I/O Setting Editable?
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0 4 No 03F8-03FF No
1 4 Yes 03F8-03FF No
2 3 No 02F8-02FF No
3 3 Yes 02F8-02FF No
4 4 No 03E8-03EF No
5 4 Yes 03E8-03EF No
6 3 No 02E8-02EF No
7 3 Yes 02E8-02EF No
8 Variable Yes Variable Yes
COM 1 defaults to Basic Configuration 0. The IRQ can be changed by selecting
Basic Configuration 1.
COM 2 defaults to Basic Configuration 2. The IRQ can be changed by selecting
Basic Configuration 3.
COM 3 defaults to Basic Configuration 4. The IRQ can be changed by selecting
Basic Configuration 5.
COM 4 defaults to Basic Configuration 6. The IRQ can be changed by selecting
Basic Configuration 7.
Basic Configuration 8 can be used to configure additional COM ports because it
lets you change the IRQ and the I/O address.
Example
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The following is a sample procedure for changing the IRQ for COM 1:
1. Click the Start button on the taskbar.
2. On the Settings menu, click Control Panel, then double-click the System
icon.
NOTE: You can skip steps 1 and 2 if you use the right (secondary) mouse button
to click the My Computer icon and then click Properties.
3. Click the Device Manager tab, double-click Ports (COM & LPT), then
double-click Communications Port (COM1).
4. Click the Resources tab.
NOTE: COM 1 defaults to Basic Configuration 0, and the settings are according
to the table above.
5. Click the arrow next to the Setting Based On box, and click Basic
Configuration 1.
6. Under Resource Settings, double-click Interrupt Request (or IRQ), then click
the up or down arrow to change the Value field setting.
7. Click OK and restart Windows when you are prompted.
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Keywords : kbhw kbHardware
Technology : kbWin95search kbWin95
Issue type : kbinfo
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