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From: rfarris@rfengr.com (Rick Farris)
Newsgroups: comp.dcom.modems
Subject: Re: Help: Why MNP5?
Summary: MNP5 is good for 2400.  280 cps transfers of compressed data possible.
Message-ID: <1991Jan28.031338.10443@rfengr.com>
Date: 28 Jan 91 03:13:38 GMT
References: <0cD8V3w163w@ozonebbs.UUCP> <1991Jan27.160653.7104@nstar.rn.com> <15126@celit.fps.com>
Organization: RF Engineering, Del Mar, California
Lines: 29

In article <15126@celit.fps.com> billd@fps.com (Bill Davidson) writes:
In article <1991Jan27.160653.7104@nstar.rn.com> larry@nstar.rn.com (Larry Snyder) writes: 

Larry> MNP5 over a 2400 baud connection if properly
Larry> installed will produce transfer rates of 280 cps even
Larry> sending GIFs and ZIPs

Bill> I find this *VERY* difficult to believe...280cps seems
Bill> impossible.  The theoretical max for 2400 baud is
Bill> something like 266cps (8 data + 1 stop) and anything
Bill> higher would require compression...

Get a clue, Bill.  Larry said he got 280 cps using MNP5 from
experience.  So have I.  None of your "beliefs" will affect that.

In particular, "perfect" 2400 bps, 8,n,1 transimission
achieves 240 cps; 1 start bit, 8 data bits and 1 stop bit.
By stripping start and stop bits, the data rate can reach a
theoretical 300 cps (240 * 10/8).  Add protocol overhead,
and a little bit of file expansion due to trying to compress
pre-compressed data and you're in the neighborhood of 280
cps.

Note that we're talking about MNP *5* here.


--
Rick Farris  RF Engineering POB M Del Mar, CA 92014  voice (619) 259-6793
rfarris@rfengr.com     ...!ucsd!serene!rfarris      serenity bbs 259-7757