Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!rutgers!att!mcdchg!ddsw1!corpane!sparks
From: sparks@corpane.UUCP (John Sparks)
Newsgroups: comp.sys.amiga
Subject: Re: 9600 bps Modems
Message-ID: <879@corpane.UUCP>
Date: 6 Jul 89 16:15:02 GMT
References: <4533@crash.cts.com> <408@xdos.UUCP> <3686@ddsw1.MCS.COM>
Reply-To: sparks@corpane.UUCP (John Sparks)
Organization: Corpane Industries, Inc.
Lines: 37

In article <3686@ddsw1.MCS.COM> karl@ddsw1.MCS.COM (Karl Denninger) writes:
 >>And in Unix land, about 95% are Trailblazers. So I guess you've really
 >>got to make up your mind whether your long term interest is in e.g.
 >>UUCP transfers or in bulletin boards.
 >
 >Right.  And the reason?
 >
 >HSTs get about 240 cps on UUCP calls!  That is right -- 2400 baud, even in
 >fast 9600/19200 baud mode!  Why?
 >   
 >   HST's backchannel won't accomodate the "ACK"s on the packets --
 >   meaning that every time you get an ACK, the line turns around. 
 >   Throughput goes in the toilet.

Yea, and not only do they suck on UUCP, but they are terrible at file transfers
of any type at anything over 2400 baud for the same reason. Downloading from
BBS's is murder using xmodem and you might as well go out to a movie and check
back the next day if you are using kermit at 9600. Xmodem 1k, Ymodem and Zmodem
are fairly fast because they send long packets before they request ACKs. xmodem
uses 128 byte packets and kermit uses 80 bytes (or is it 78?) and they expect
an ACK for each packet. so the line keeps switching between 9600 and 2400 baude
every 128 or 80 bytes. REAL SLOW. At least that is what seems to be happening.
I can transfer a file faster using kermit or xmodem at 2400 baud than using
kermit or xmodem at 9600 baud on a HST.

The HST is great if you are just hooking up to a BBS to read text (i.e. just
use the HST and computer as a terminal), but forget it for file transfers
unless you use ymodem or zmodem.

The new HSTs and the new Trailblazers both support V.32 which is a protocol
that should support 9600 both ways, and should solve the HST mode problems and
make them compatible with each other.

-- 
John Sparks   |  {rutgers|uunet}!ukma!corpane!sparks | D.I.S.K. 24hrs 1200bps
|||||||||||||||          sparks@corpane.UUCP         | 502/968-5401 thru -5406 
As far as we know, our computer has never had an undetected error.