Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!vsi1!wyse!mips!greg
From: greg@mips.COM (Greg Shippen)
Newsgroups: comp.sys.mac
Subject: 2400 baud modems and scrolling
Keywords: Modems screen-updating
Message-ID: <2649@quacky.mips.COM>
Date: 22 Jul 88 06:24:57 GMT
Reply-To: greg@mips.COM (Greg Shippen)
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 35


I have a rather puzzling problem with my Mac Plus when attempting
to use it with a 2400 baud modem.  Because my Prometheus modem has the
LED lights on the front, I can tell that the time required for the data to
move across the phone line and thence to the Mac and the time to scroll the
data on the screen is *different*.  In short, I seem to be communicating 
over the phone at 2400 baud, but the Mac appears to want to give it to me 
at a significantly slower baud rate.  In a typical case, the data has finished 
arriving over the phone several seconds before the scrolling stops on the 
screen.  (Yes, I do have my terminal program set at 2400 baud.)

I have been using RedRyder (8.0), but the problem remains unchanged 
using VersaTerm (1.0).  It seems clear that the data is being buffered 
within the Mac, it just seems like the Mac can't update the screen fast 
enough.  This was my reasoning until I discovered somebody here who was 
using a Mac as a terminal at 9600 baud! Clearly, the Mac *can* keep up.

Can anybody diagnose my problem?  What am I doing to keep me from taking 
full advantage of my 2400 baud modem?

To be specific about my setup, I am running a Mac plus with Rodime 20 plus.
I have Finder 6.0, System 4.2.  The system is rather large, as I have lots 
of fonts added (it comes to 360K).  Also, I have installed two cdevs: Moire
and SoundMaster.  I have only a few of the usual DA's.

I have had the problem before installing the cdevs, so they do not appear to
be the problem.  Also, I tried using a old stripped down Finder (5.3) and 
system.  This time the problem did seem to go away!  Naturally, I would 
like to avoid having to use the old system just to use my modem.


-- 
================================= Greg Shippen ==============================
By phone: (408) 991-7727   By ARPANET: mips!greg@ames.arc.nasa.gov 
By UUCP:  {ames, prls, pyramid, decwrl}!mips!greg
=============================================================================