A Higher Speed Limit For Downloaders

YOU KNOW THOSE WINDOWS that pop up on your screen during a file transfer, saying how many bytes have been sent and how much longer it will take? Well, the horsepower that goes into displaying that information can slow the transfer by a third, in the case of a 486 personal computer running a high-speed connection such as ISDN.

Pacific CommWare Inc. in Ashland, Ore., has a software utility for Windows 95 called TurboCom 95/Pro that shows more information about the data connection and pays a speed penalty of about 1%, according to John S.H. Loram, president and CEO. It notes the data flow rate and long-term average flow rate, and it records any errors.

The original TurboCom software was designed in 1991 as a way to work around the speed limitations of Microsoft Corp.'s Windows. Back then, Windows was designed to work with serial-port chips called UARTs that could hold only one byte of data in their buffers. If data came too quickly, the computer's processor couldn't scoop it out of the small buffer in time to prevent a backup. Microsoft tried to deal with that in Windows 95 by supporting UART chips with 16-byte buffers. But a bigger buffer isn't enough for 33.6-baud modems or ISDN connections using data compression, says Loram. TurboCom 95/Pro supports UARTs--such as a new one from Texas Instruments Inc.--with 64-byte buffers.

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