Date   : Fri, 08 Feb 1991 00:49:11 GMT
From   : munnari.oz.au!uniwa!vax7!nmurrayr@uunet.uu.net
Subject: Is my machine too SLOW for 2400bps modems?

In article <316@fxrs.intel.com>, jmasters@fxrs.intel.com (Justin Masters)
writes:
> 
> I have a Radio Shack model 4 w/ Montezuma Micro's CP/M 2.2.  I bought a 2400
> buad modem a few months back, and while I've endured a problem with not
> getting the first characters of the line, I can't stand this problem anymore.
> 
> I'm using Qterm 4.2f and I've also used MEX 1.12 (or some old version like
> that).  Both worked beautifully for me when I had 1200 baud capability, but
> now it seems that 2400 baud is too fast.  Is this true?  How do I fix it?  Is
> it a problem of my machine waiting too long at the end of the line before
> continuing on to the next line?
> 
> This is really annoying, and as I have wanted to get on a couple of new
> bulletin boards around town, I can't effectively use them, since they're menu
> driven, and the first 3-4 characters are lost, I can't read what character to
> use for a particular function.  Sometimes it's intuitive, but most are not.
>  

   If you were losing characters at the start of each line at 1200 baud, then
you're going to lose twice as many at 2400. The problem is caused because the
processor must scroll the screen up one line whenever it sees a line feed. If
your system has a separate video controller then it doesn't usually take too
long and characters are rarely lost even at high baud rates. If your main
processor has to do all the work then characters will probably be lost. The
original Apple IIs with 80 column cards were bad in this respect: they'd
even lose about 5 characters at 300 baud.
   The solution depends on the BBS you're calling, as there's probably nothing
you can do to fix it at your end. Most BBS programs will let you specify a
number of nulls at the start of each line. Try selecting some and see if it
helps.

....Ron

-- 

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