[ct-user] Dropped Chars on TNC Interface

Charlie and Janet Ross Charlie and Janet Ross <ross_family@acm.org>
Thu, 30 Dec 1999 22:19:04 -0500


Good News: My 386/16 contesting computer is being replaced by a 486/133.

Bad news: I'm having problems with CT and COMTSR3 talking to the TNC.

Configuration:
Win95 booted to DOS.
COM 3, standard base address, IRQ 9.  (Byte Runner dual-serial, ISA, 
16550-compatible adapter card).
TNC strapped for 4800 baud; COMTSR3 given -b4800 (used to work fine on 386).
Symptoms the same whether I issue -i9 or not (I saw in an old post that 9 
was COMTSR's default for COM3; giving it -i10 breaks it), or whether I use 
flow control switches, or how I set flow control.

Symptoms:  Getting first and last characters of a line, and some in 
between, some may be corrupted.

I had a similar problem on the 386 which I solved by dropping the baud rate 
from 9600 to 4800.  I figured that the CPU just couldn't service the 
interrupts fast enough.  I didn't expect to see the same problem on the 
486, since it's so much faster.  Although the IRQ is higher (lower 
priority?), I don't expect there's a whole lot more demanding the CPU's 
attention in MS-DOS mode.  But I'm no expert.

Any suggestions would be welcome.  I'll keep playing with it.  The port 
works fine--at this baud rate--when the PC's booted to the Windows GUI and 
using Windows apps (and the Windows driver).

Thanks...

--Charlie



------------------------------------------------------------
                     ross_family@acm.org
------------------------------------------------------------
Charlie Ross                         Janet Ross
Amateur Radio Operator NC1N          Cross-Stitch Enthusiast

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