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From: rhiggins@carroll1.cc.edu (Ron Higgins)
Newsgroups: comp.sys.apple2.comm
Subject: Re: ProTERM questions
Date: 27 Jun 1994 20:43:46 -0500
Organization: Lightning Systems
Lines: 54
Message-ID: <2unv8i$g2r@carroll1.cc.edu>
References: <2uejdi$b3g@kruuna.Helsinki.FI> <2uksjl$jto@jadzia.csos.orst.edu> <2unt2v$nmk@apple.com>
NNTP-Posting-Host: carroll1.cc.edu

In article <2unt2v$nmk@apple.com> unknown@apple.com (Matt Ackeret) writes:
>>: It seems to be practically common knowledge that
>>: transfers will speed up (if you have a hard drive and
>>: a RamFAST, at least). Where is this information? Doesn't seem to be in
>>: the manual...
>>	 Set $l = 1.
>
>	I rearranged some lines in the stuff I'm quoting..
>	Anyhow, why do you say set $l =1 will speed things up?
>	I have $L set to 0, which is "streaming"..

I too have rearranged some things in the stuff that I quoted.
I'm going to attempt to explain the difference between $l=0 and $l=1.

$l=0 will set ProTERM up to use the maximum buffer size it can when doing
transfers.  This mean that during uploads ProTERM will fill read data from
the disk into the buffer (46k or so) and then start sending the data.
During downloads ProTERM will receive data into the buffer until it fills
up (46k or so) and then pause the transfer while it writes the data from
the buffer to the disk.  This is pretty fast is you are writing to a RAM
disk or to a RAMfast buffered hard drive.

$l=1 will tell ProTERM to stream the transfers to disk.  During a download
ProTERM will pause the modem (via hardware handshaking) to write the data
to disk after every XXXXX, (I don't know how many bytes, someone said
ProTERM will write to disk after every byte but that doesn't seem right).
What happens is that the modem no longer sends data to the computer but
continues to receive data from the host computer into it's buffer (most
modems have a data buffer).  Once the modem buffer fills up the host
computer must stop sending data otherwise data will be lost, BUT what
happens in reality is that the local computer finishes writing the data to
disk and tells the modem to start sending data again.  This happens before
the modem buffer fills up, so what's now in the buffer gets transfered to
the local computer at maximum speed (19.2k, 38.4k, 57.6k, etc...) and then
starts the process over again.

The beauty of this is that the host computer never has to stop sending
data.  With $l=0 the local computer has to tell the host computer to stop
sending data while it writes the buffer to disk.  That never happens with
$l=1.  All this handshaking takes time.

I hope this is clear enough for everyone.  Bottom line is that if you have
a high speed modem and are using a hardware handshaking cable, use ProTERM
v3.1 and have a RamFast hard drive controller, you should 'SET $l=1' in
your PT3.GLOBAL file under the @@1 label.  You will need to restart ProTERM
for this change to take affect.

[disclaimer: I don't not work for InTrec, just use ProTERM and think it's a
great program.]
-- 
Ron                         |_    Lightning Systems       | Lightning Systems
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