Setting up a Trailblazer on Microport 286

[Michael Grenier]

>From article <489 at wa3wbu.UUCP>, by john at wa3wbu.UUCP (John Gayman):
> 
> 
> 
>    Before I gave my first impressions of the Telebit Trailblazer running
> under Microport Sys V/AT.  I have put together a list of exactly how I
> have everything set up. 

I looked over the list John provided us but I'm lost over one
point. I running a MultiTech 224E, 2400 baud modem with MNP 5
error correction which means that it incorporates compression
on the fly like the Telebit. My maximum throughput then is nearly
4800 baud on text files. 

I can set up the microport box for 4800 baud and let the modem do the
baud adjustments for me but heres where I run into a problem. If the
modem starts talking to something around 2400 or 1200 baud then the
transmit buffers will overflow in the modem ( duh, really?). OK, there
are two types of flow control I can use.

The first is the obvious Xon, Xoff which works fine for text files
but is dubious when I'm using XMODEM or other binary file
transfers (I'm assuming that the UUCP g-protocol is also binary).

The other method is to use hardware handshaking. This modem uses
CTS to signal the Microport box to stop transmitting and uses RTS
to allow the Microport box to signal the modem to stop sending to
it. It seems according to Microport's tech support that their 
serial drivers don't support hardware handshaking - which can't
be too tough if IBM can do it in their BIOS :-). How can I make
used of the speed advantages of this MNP5 modem and still
allow it to handle calls from 1200 and 2400 baud modems.


    -Mike

{rutgers, amdahl, ihnp4}!bungia!cimcor!mike