https://wiki.swcp.com/w/index.php?action=history&feed=atom&title=KB_43 2026-10-07T18:21:25Z Revision history for this page on the wiki MediaWiki 1.45.1 https://wiki.swcp.com/w/index.php?title=KB_43&diff=545&oldid=prev 2008-06-05T23:51:15Z

<p>New page: ===COM Port Overruns in Windows NT 4=== Article:43 Created:1999-09-01 16:39:54 Categories: Windows NT 4 ====Question or Symptom==== How do I stop COM Port Overruns in Windows NT 4? ...</p> <p><b>New page</b></p><div>===COM Port Overruns in Windows NT 4===<br /> Article:43<br /> Created:1999-09-01 16:39:54<br /> Categories:<br /> Windows NT 4<br /> <br /> ====Question or Symptom====<br /> How do I stop COM Port Overruns in Windows NT 4?<br /> <br /> <br /> ====Resolution====<br /> In Windows 95 there is a slider in the Modem control panel which<br /> lets you modify the FIFO triggers for your COM Ports to improve<br /> performance. There is no such control under NT 4.0, so you have to<br /> edit the registry to accomplish the same goal.<br /> If you&#039;re seeing COM port overruns in NT4, try the following.<br /> WARNING: Editing the Registry in NT or 95 is a dangerous<br /> undertaking! Be sure to back up your Registry before editing it.<br /> Beware that if you screw this up your computer may become<br /> unbootable! Be careful!<br /> <br /> 1. Run the registry editor, go to<br /> HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Service/Serial<br /> 2. Change RxFIFO RegDWORD from 8 to 2<br /> <br /> This changes the FIFO to trigger after 2 bytes are available to<br /> send instead of waiting for 8, which reduces the chance that the<br /> FIFO will fill up and overflow before your machine is able to<br /> transmit the bytes. A setting of 4 may be acceptable as well, and<br /> result in slightly better performance. Some experimentation may be<br /> necessary.</div>

Jamii