This is probably the wrong place to ask the following, but it
is the only place I've found so far that is at all related to
our problem. If this is not something you deal with, perhaps you
could let me know where to take it?
Here's the deal: We have a MicroVAX running some kind of VMS.
We are replacing dumb terminals with PCs. We are having a lot
of trouble with laptops that can't connect reliably as serial
terminals. We are using Windows 95, although we had the same problem
with Windows for Workgroups. Our terminal emulation program is
Procomm 2.1, and it works fine on our desktop PCs, but on the
laptops it usually is extremely garbled with lots of high ASCII
characters. Occasionally, a laptop works fine. We are baffled.
I suppose it could be a hardware problem, but I have no idea what
kind.
Thanks for any help.
The symptoms you describe are typical of having a serial line
controller in the laptop that cannot keep up with the high data
rate being used. You don't say whether the modem is external or
internal on the laptops, but if external, and the laptop does
not have a 16550 (or compatible) high-speed UART chip, then you
will be limited to 9600 baud as the chip can't handle faster rates.
The Windows 95 Device Manager can tell you what kind of chip is
being used for the serial port.
If you are using an internal modem, then the UART issue does not
apply. Make sure that the modem serial port's properties are set
to a high baud rate (57600 or 115200).
It is unlikely that the problem is on the OpenVMS end of the connection,
since as you say the desktop systems work fine.
