COMxFIFO Does Not Properly Understand True and False

 Last reviewed: November 23, 1994
Article ID: Q84873
The information in this article applies to:
  • Microsoft Windows operating system versions 3.1, 3.11

SYMPTOMS

The SYSTEM.INI [386Enh] setting COMxFIFO= does not correctly understand True/False, On/Off, or Yes/No. Using any non-numerical value sets the switch to "0" and therefore disables the FIFO.

CAUSE

The COMxFIFO= setting is not fully Boolean aware.

STATUS

Microsoft has confirmed this to be a problem in Windows version 3.1. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

WORKAROUND

Use the following settings: 

   COMxFIFO=1 (On)

   -or-

   COMxFIFO=0 (Off)

MORE INFORMATION

This switch is used to enable or disable Windows 3.1 support for Windows-based applications using a COM port with a 16550 Universal Asynchronous Receiver Transmitter (UART). The 16550 has a 16-byte character FIFO buffer, or first-in, first-out buffer.

The SYSINI.WRI file from the Microsoft Windows Resource Kit (WRK) for version 3.1 incorrectly identifies TRUE/FALSE as functioning with this switch. Page 196 of the WRK guide incorrectly identifies On/Off as functioning with this switch.

For more information on this setting, query on: 

   COMMQ&A and windows 3.1

KBCategory: kbenv kbdocerr kbbuglist
KBSubcategory: wincomm win31
Additional reference words: 3.10 3.11 crc xmodem documentation error doc
err

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Last reviewed: November 23, 1994
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