Message-ID: <1039@sunybcs.UUCP>
Date: Wed, 16-Jan-85 15:01:40 EST
Article-I.D.: sunybcs.1039
Posted: Wed Jan 16 15:01:40 1985
Date-Received: Wed, 16-Jan-85 17:40:27 EST
Distribution: net
Organization: State University of New York @ Buffalo,NY
Lines: 122
Xref: watmath net.micro:9067 net.micro.pc:3127

[ Where did that clutter on my screen come from? ]

A short while ago I posted an article asking for help about my Qubie
1200 baud modem.  I kept getting line noise, causing garbage on my screen.
Going on the responses I got, it seems that the Qubie is not such a great
buy for the low price after all.  It seems to perform well at 300 baud, 
but that it not what I bought it for.

I would also like to thank all who responded to tell me that it is not
just my problem, but a flaw in the Qubie design.  (I strongly doubt my
problem is caused entirely by noisy phone lines - I had been using a
300 baud modem with another micro for 2 years without this sort of problem.)
I have since made arrangements to replace the Qubie with a Hayes 1200b!

Appended below is a summary of my mailbox, intended to help any potential
modem purchasers.

Mark J.

======================================================================

Sometimes the VADIC which we use at 1200 will generate spurious characters
on some phone connections.  I would guess that there is crosstalk which
the modem interprets as characters.  The solution has been to re-make
the telephone connection, hoping to get either a quieter line or modem
on the other end.

=========================================================================

I've been using this modem for a bit more than a year now.  It doesn't
work too well.  (But I spent the money, so I'm bearing it.)  In addition
to the noise you mentioned (usually only in the evenings) it has great
difficulty in making its first connection.  Sometimes I have to try 3
or 4 times.  I get the tone from the host, but my modem won't answer.
And sometimes it hangs - the only way out is cycling the power.
   I find that the noise problem only occurs in the evening, and so I
have always assumed that it is my Telco's problem.  If others are having
this problem with Qubie modems (and not with other modems) then I guess the
problem must be Qubie's.

=========================================================================

I bought a QB last year at this time and had problems.  I exchanged
it and got another that performed equally poorly.  The  solution
to the problem was to return the QB and buy a Hayes.   After the
frustration of using the QB, the extra $100 seemed well worth it.

My opinion is that a design flaw and/or low tolerance components
cause the QB to lose phase lock of the recieved signal very easily.
The result is frequent strings of random characters.

Noise on the line causes occaisional "{" characters to appear.
If you get random bursts of junk, it's the modem.

========================================================================

I am not familiar with the QUBIE 1200, however, I have a Racal Vadic modem
and also experienced some severe noise problems at home.  I later discovered
that my problem was caused by my wireless phone.  Unplugging the phone from
the jack while the modem was in use cleared up the noise problem.   Secondly,
the phone company does not guarrantee the phone lines for data connections
unless you so specify.  In other words, for the cost of another phone line
Ma Bell will assure you of a noise free connect to any other phone hhaving
a noise free connection.

========================================================================

I have been using my QUBIE plug in board in my IBM PC for almost a year.
I have never had a problem with garbage, though with Signalman 300
baud it was terrible. The only problem I have hadd is the damn thing answering
the phone on voice calls, or answereing on no call.

I'm happy with it, especially at the price.

========================================================================

Mark - I almost bought the same modem as you did; not wanting to pay
the amount for an overprice Hayes S
martmodem.  When I called to buy it at a well known place (I beleive it
was compu-add ) they said they had just dropped it because 50% of them
were being returned.  It seems that they work fine at 300 baud but don't
cut the mustard at 1200.  I would try to return it as soon as poosible and
get one of the low priced Hayes compatables.  (Password etch...).

=======================================================================

I don't know much about the Qubie, but the problem may not
be with the modem.  Do you really get extraneous characters,
transmitted characters that got mutilated, or dropped characters?
Depending on which of these symptoms you have, you ought to look
for different problems:

SYMPTOM					LIKELY CAUSE

Mutilated characters			Modem

Extra characters, especially 		Line
   during quiet intervals.

Dropped characters			The terminal emulation program
					may be having trouble keeping
					up at 1200 baud.

=========================================================================

	I have a Prometheus Promodem 1200 and am experiencing similair problems
of the extraneous char. variety. mainly I recieve extra {'s (only at 1200). I
sent the modem back for a replacement and still am having the same problem but
to a slightly lesser degree. this time I sent it back to the manufacturer to
see what they may be able to do. 1/3 of the connections I get are totally 
poor, and the rest of the time I average 1 garbage char. per 1 to 2 min.

	I suspect the problem is a combination of poor noise filtering by
the modem and poor university 1200 baud modem connections.

==========================================================================


Mark D. Johnson                   SUNY/Buffalo Computer Science

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