🚀 go-pugleaf

baer@uwovax.uwo.ca writes:

>I am running a communications app. which comes in both a DOS and an OS/2
>version (Rexxterm).  I just purchased a 9600 baud modem for my 16mHz
>386sx.  This modem has MNP 5 (and v.42) error correction; of these 2,
>the modem at the "mainframe" end seems to provide MNP 5 but not v.42.
>MNP 5 should provide a throughput of up to 19,200 baud.  Under Windows 3,
>when I run the serial port at 19,200 baud and connect at 9600 baud,
>I lose characters, even with the communications app. running in the
>foreground and no major app's running in the background (file system,
>pgm. manager that's all).  With the serial port set at 9600 baud, 
>I have no problem with the comm. program in the foreground.  With any
>serious multi-tasking in 386 enhanced mode, even this configuration 
>(9600 serial port speed) isn't low enough: there is a loss of characters
>when I run the com. program in the background (priority=100) and
>either Word Perfect or a stats program in the foreground (priority=100).
>This despite the fact that the foreground program suffers some 
>degradation (typed characters take a while to appear on screen etc.).

>Under DOS alone, there is no problem running the communications 
>program with the serial port set at 19,200 baud.

There's a tech note from Microsoft (last updated 10 December 90) which
addresses lost data running at 19.2 or higher using KERMIT.

Its suggestions (which I haven't tried since I'm limited to 9600 bps)
are:

  - mark "Lock Application Memory" in the PIF file

  - Set COMxBUFFER to a big value (1024 suggested as a start)

  - Set COMBoostTime to a higher value (10 msec suggested)

  - Set COMxProtocol to XOFF (and use XON/XOFF in REXXTerm)

It also suggests that KERMIT users turn the timer off because delays
between characters caused by Windows' buffering can make Kermit think
it's got a dead circuit.

Joe Morris