Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!mp.cs.niu.edu!ux1.cso.uiuc.edu!orion!ignacij From: ignacij@orion (Ignacy Misztal) Newsgroups: comp.os.os2.misc Subject: Serial port and 16550 chip Message-ID: Date: 28 May 91 16:32:06 GMT Sender: usenet@ux1.cso.uiuc.edu (News) Organization: University of Illinois at Urbana Lines: 14 I run Kermit under OS/2 using a 9600 baud modem with v.42bis data compression that can be connected up to 38,400 baud. A version of Kermit (VIO) runs at 19,200 baud using almost all CPU time but the newer versions for PM with sliding Windows run marginally (only when display is in 800x600 mode but not in 640x480!). Probably interrupts took most CPU cycles. Several publications recommend exchanging the common, non-buffered SIO cotroller 16450 by a newer chip 16550, with 10 character FIFO. Will OS/2 take advantage of this chip automatically, reducing the number of interrupts, or does the application have to do it? ===================================================================== Ignacy Misztal Internet:ignacij@orion.animal.uiuc.edu University of Illinois Bitnet: ignacy@uiucvmd 1207 W Gregory Dr. Phone: (217) 244-3164 Urbana IL 61801 =====================================================================