nt to understand how Windowshandles incoming data transmissions. Your modem sends the data it receives toWindows' COMM driver. This stores the received data in a memory buffer untilyour communications program retrieves it. Unfortunately displaying and storingall the received data keeps your communications program working overtime. As aresult, it can't always retrieve data from the COMM driver as often as itneeds to.By default, Windows sets aside just enough buffer space to store 128 incomingcharacters. Unfortunately, once a modem has been connected, data flowscontinuously. Your computer can temporarily stop the flow of data, but doingthat takes time. Meanwhile, data continues to arrive and must be stored in theCOMM driver buffer. If your communication link is slow, or your communicationprogram is fast, a 128-character buffer might suffice. But with a fast modemor a slow program, it's possible for more than 128 characters to arrive beforeyour program can process them. In that case, the COMM driver has no place tostore the 129th character and those that come after it.Luckily, you can expand Windows' COMM buffers. By adding a line to the[386enh] section of the SYSTEM.INI file, you can create a buffer as large as10,000 characters. Actually since the COMM driver maintains a buffer for eachof your PC's COM ports, you can add up to four lines, each controlling thesize of a particular port's buffer. Each line should resemble this:COMxBuffer=numReplace the x with a number between 1 and 4 to indicate the desired COM port,and substitute num with a number from 128 to 10,000 to set the buffer size.You have to exit and restart Windows for the change to take effect. Use a texteditor when editing SYSTEM.INI.As for how big should your COMM buffer be, if characters are being droppedfrom incoming data transmissions, create a new buffer of at least 2,048(2KB) characters. If problems persist, increase the size of the buffer to4,096 (4KB) or even 8,192 (8KB)...
