Windows 2000 / XP:

1. Open the Control Panel (Start Menu -> Settings -> Control Panel).
   
2. Double-Click on System.
3. Select the Hardware tab in the System Properties window.
   
4. Click on the Device Manager... button.
5. Expand the Ports (COM & LPT) tree by clicking the plus sign.
   
6. Double-Click on Quatech PCMCIA Serial Port (COM?).
7. Select the Port Settings tab in the properties window.
   
8. Click on the Advanced... button.
   
9. To turn FIFO buffers off: make sure the option Do not use FIFO buffers is selected.

Windows 95/98/ME:

1. Open the Control Panel (Start Menu -> Settings -> Control Panel).
2. Double-Click on System.
3. Select the Device Manager tab in the System Properties window.
4. Expand the Ports (COM & LPT) tree by clicking the plus sign.
5. Double-Click on Quatech PCMCIA Serial Port (COM?).
6. Select the Port Settings tab in the properties window.
7. Click on the Advanced... button.
8. To turn FIFO buffers off: make sure the check box next to Use FIFO buffers is unchecked.

Windows NT:

1. Open the Control Panel (Start Menu -> Settings -> Control Panel).
2. Double-Click on Ports.
3. Select the communications port you wish to change.
4. Click on the Settings... button.
5. Click on the Advanced... button.
6. To turn FIFO buffers off: make sure the check box next to FIFO Enabled is unchecked.

General help with Quatech cards:
http://www.quatech.com/support/rs232pcmcia_faq.php