[comp.windows.ms] Windows 3 and COM ports

tj@gpu.utcs.utoronto.ca (Terry Jones) (05/31/90)

Love Windows 3.

Had some problems with Kermit communications package running under
386 enhanced mode. I could talk to the device but the responses didn't
come back to the screen (program). In real mode all was well (win /r).

I looked through sysini txt files and found a reference to COMnBASE=xxxxh
which specifies the base address of the com ports and the COM3 and COM4
addresses were (I think) the IBM chosen ones not the ones that my modem
uses (3E8 2E8) and when I set them correctly things worked fine. 

Just thought someone else might be interested!

altman@sbstaff2.cs.sunysb.edu (Jeff Altman) (05/31/90)

In article <1990May31.022051.27093@gpu.utcs.utoronto.ca> tj@gpu.utcs.utoronto.ca (Terry Jones) writes:

>Had some problems with Kermit communications package running under
>386 enhanced mode. I could talk to the device but the responses didn't
>come back to the screen (program). In real mode all was well (win /r).

This was true of the Windows 3.0 Beta but not of the release version.
Somehow Windows was blocking the Interrupts that state that a character
has been received by the UART.  It didn't block other interrupts such
as Overflow, etc.

I am currently writing this note with MS-Kermit 3.01 in a Windows
in Enhanced 386 mode.  And it works great!  Or at least as good
as a DOS App doing interrupt driven communication via a serial line
can be in a Multitasking Environment.

This is where a true Windows App can really shine, communications
in bcakground. 

>I looked through sysini txt files and found a reference to COMnBASE=xxxxh
>which specifies the base address of the com ports and the COM3 and COM4
>addresses were (I think) the IBM chosen ones not the ones that my modem
>uses (3E8 2E8) and when I set them correctly things worked fine. 

Okay, well this makes sense as well.  

>Just thought someone else might be interested!

me too.

- Jeff (jaltman@ccmail.sunysb.edu)