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Conference giadev::decstation

Title:DECstation PC Conference
Notice:register note 2, see notes 3 & 4
Moderator:TARKIN::LININD
Created:Tue Jan 10 1989
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:7470
Total number of notes:34994

7358.0. "FX's and UART speed sutainability?" by SNOFS1::16.153.96.192::powellronald (Australia!) Wed Feb 19 1997 21:49

Bill/Chet, Can either of you confirm whether the Venturis/Celebris FX 
5xxx serial UARTs can transfer data at a 'sustained' rate of 115kbs 
using a null modem cable? I know the machines have "16550"s in them 
but the customer needs to know if the full speed can be acheived. If 
the UARTs can  run long periods at this speed but cable type/length 
limitations are involved, please let me know what the rules are.

 Many thanx,
 Ron .
T.RTitleUserPersonal
Name		DateLines
7358.1my opinionTARKIN::LINBill LinThu Feb 20 1997 07:0521
    re: SNOFS1::16.153.96.192::powellronald
    
    Ron,
    
    Under the right conditions, even ancient 8088 processors can drive a
    UART at 115kbps.  But there's no way anyone can guarantee those speeds
    without first characterizing the environment.  It would be easiest
    under a single-tasking environment such as MS-DOS.  Win3.1/Wfwg/Win95,
    don't even hint that it can be done.  It would be easy to mess up, and
    we'd get sued.  WinNT, maybe.  Again, it would be possible to mess up,
    and again, we'd get sued.
    
    Don't make any claims unless you're ready to first test/qualify it, and
    then only use a real-time operating system.  I don't consider any of
    the above mentioned ones real-time OSes.
    
    Maybe I've overreacted.  I prefer to err on the side of caution.
    
    Regards,
    
    /Bill
7358.2FX and UART speedPCBUOA::GKELLEYThu Feb 20 1997 12:1310
    The Venturis/Celebris FX use the SIS 5513 for serial IO. The chip is
    spec'd at 115kbs. Bill's point as to whether or not the OS can support
    this speed is correct.
    
    I would suggest that the customer run a test to see if the application
    can run at this speed, the chip is capable of it.
    
    regards,
    
    glen kelley
7358.3thanxSNOFS1::16.153.96.192::powellronaldAustralia!Tue Feb 25 1997 01:252
Thank you, 
  Ron.