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From: tnixon@hayes.uucp
Newsgroups: comp.dcom.modems
Subject: Re: Intel 9600EX
Message-ID: <3742.279dc592@hayes.uucp>
Date: 23 Jan 91 17:19:14 GMT
References: <9101190810.AA02289@ucbvax.Berkeley.EDU>
Organization: Hayes Microcomputer Products, Norcross, GA
Lines: 32

In article <9101190810.AA02289@ucbvax.Berkeley.EDU>,
CHARLIE@UMVMA.BITNET (Charlie Turner) writes: 

> I was somewhat surprised (due to lack of prior experience with dial
> 9600 speed modems) at how long it takes for these modems to establish
> connection after the phone answers. The average time was 20-30 seconds.
> Is this normal?

Yes.  Because of the need to measure the propagation delay and train 
both adaptive equalizers and echo cancellers, it takes V.32 modems 
anywhere from 10 seconds and up to connect, longer on bad lines. 
Plus, after the carriers connect, you still have another second or
two of protocol negotiation. 

> The only minor problem I had was (I think) due to COM port overrun. I
> run DesqView. That combined with the 38.4kbps interface speed likely
> means I need to get a 16550 buffered UART. The simptom was Zmodem asking
> for retransmissions when the modem connection was in fact operating in
> reliable mode. When I tried using Ymodem-G the download was aborted on
> my end, making me suspect the problem lies between the modem and my
> comm program.

I'd say you definitely need a 16550, with software that knows how to 
use its FIFOs, if you're going to run under Desqview.  Data loss due 
to interrupt latency is undoubtedly the cause of the problems you 
saw.

-- 
Toby Nixon, Principal Engineer    | Voice   +1-404-449-8791  Telex 151243420
Hayes Microcomputer Products Inc. | Fax     +1-404-447-0178  CIS   70271,404
P.O. Box 105203                   | UUCP uunet!hayes!tnixon  AT&T    !tnixon
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