Path: utzoo!utgpu!attcan!uunet!lll-winken!ames!mailrus!bbn!oberon!pollux.usc.edu!papa
From: papa@pollux.usc.edu (Marco Papa)
Newsgroups: comp.sys.amiga
Subject: Re: high-speed file transfer
Keywords: Amiga sun modem
Message-ID: <14618@oberon.USC.EDU>
Date: 12 Jan 89 01:24:47 GMT
References: <891@io.UUCP>
Sender: news@oberon.USC.EDU
Reply-To: papa@pollux.usc.edu (Marco Papa)
Organization: Felsina Software, Los Angeles, CA
Lines: 47

In article <891@io.UUCP> dbjag@io.UUCP (David Benjamin x4050) writes:
>Does anyone have a method of transferring files over a *high-speed* modem
>connection between an Amiga and a Sun (4.2 BSD UNIX)?  The connection is
>through a pair of US Robotics Courier HST modems connected at 9600 baud (ARQ).
                   ^^^^^^^^^^^^^^^^^^^^^^^                     ^^^^^^^^^
>I currently use Kermit for file transfers, but because of its constant error
>checking it clogs the hell out of the high-speed connection protocol employed
>by the modems.  It is actually faster to reconnect at 2400 baud to transfer
>using kermit than to use 9600 baud.

This is of course "commercial", BUT I've been using the US Robotics COURIER HST
at 9600 baud with A-Talk III for quite a while. The current version of 
A-Talk III will be able to to send and receive with ZMODEM protocol at well 
over 1000 char/sec. I've experienced even 1200 char/sec on some long ARC files.

>I'd like to be able to transfer binary at as fast a rate as possible, 
>relying on the modems for error checking. 

The fastest A-Talk III/Courier HST speed can be obtained when using RTS/CTS
flow control, HST flow control on BOTH transmit and receive, no compression
(use ARC files), and A-Talk III baud rate at 19,200.  The proper settings
on the HST are set with:

AT&K0&H1&B1&R2

On A-Talk III select RTS/CTS and 16K input buffer from Preferences, and select
BAUD 19200.

>Is there anyone out there with a similar situation who *IS ACTUALLY USING*
                                                        ^^^^^^^^^^^^^^^^^^
>a method for high-speed binary file transfer from Amiga to a UNIX machine?
>I'd appreciate any advice, direction or war stories.

Yes, I am.  Note that the above speeds have been obtained with Channel 1,
a Mass BBS that supports the Courier HST.  Some UNIXes have problems 
receiving data as fast as A-Talk III can send, especially when not
using RTS/CTS [i which case X-o/X-off should be used for ZMODEM].
There is no problem when the UNIX box is sending files, though.

The next release of A-Talk III will contain a specific modem entry for the
Courier HST, that will select the above settings automatically (poof!).

-- Marco Papa 'Doc'
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