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[sindi keesan <keesan AT sdf.lonestar.org>]

> i cant remember what the command is but you can save configuration
> data to the modem (the command is the same for all modems... i -think-
> its W0 but double check on that) that way you wont need to juggle init
> strings around but your modem will be set as soon as you turn it on
> (ATZ or AT&F1 will be all that you need in the dialer... ATZ and AT&F1
> do the same thing as far as configs go ATZ just clears memory... makes
> for a cleaner reset)

AT&F1 works fine for me with USR, no need to change it.  Most of my modems 
are USR.  I just need to remember to use ATZ on the others.

> > S15=128 seems to keep the Sportster from attempting to use X2, so it
> > negotiates and connects faster.  The non-Sportster boings for a lot
> > longer.
>
> the 'boing boing' is the modem testing the analog frequency response
> of the phone line... the modem on the other end will answer with a
> simple beep when testing is successfull (if testing is not successful
> you will not get 56k)

So why is the internal (slight newer) modem with the slightly older flash 
taking longer to connect?

> btw, other modems make different noises for the frequency response
> test.... rockwell/conexant make a "brrrrrrrraaaAAAP" (sounds like a
> synthesiser trying to make a fabric ripping noise... or the result of
> a bean burrido) and agere intel and possibly others make a "diddledy
> diddledy" (almost like an electronic giggle)
Interesting.

> > > > S32=34 stops the Sportster from trying to connect with SX2 but has no
> > > > effect on the other USR.
> > It does not stop the Sportster, I was wrong.
>
> x2 and flex should be disabled entirely.... they are obsolete unstable
> and unused by ISPs....
I thought S15=128 was supposed to disable X2 but maybe only for the 
Sportster, which is why it connects with less boings.

Ijust had a 20 sec timeout again.

> it connected at 53333 and the line conditions changed and it realised
> that that speed wasnt stable and did a re-train and slowed itself down
> to 50666.... its also possible for 56k modems to increase the speed if
> the opportunity arrives so even if it slows itself down it may speed
> itself back up.... or it may even speed up faster than the inital
> connect speed....  add M2 to your init string to make the modems
> speaker stay on all the time and you'll hear whats going on..... itll
> get a wee-bit irritating after a while tho....

It always connects at 53333 and then ATI6 always says 50666.
My other modems run about 46-49K.  These are the best two.
(There is a newer one that is 56K but connects at 28.8K).

> i dont use eznet (i use bash chat and pppd) so i dunno what to tell
> you but if the modem supports and is using v42 but it doesnt tell you
> it supports it or tries to use MNP rather than v42 that just sounds
> like some crappy programming (welcome to the world of us robotics
> products)

It only uses MNP if I tell it S32=34

> > Is the upload same speed as download?  How fast would v90/v44 upload a
> > .jpg?
>
>
> v90 has a max downstream of 56000 (53333 in the us due to power output
> restrictions... tho this was recently changed many ISPs just left
> things alone) and a max upstream of 32000 (v90 56k modems were
> designed with only web surfing in mind... so they upload slower than a
> 33.6k modem)  v90 does not support v44 compression... only v42... v42
> does not do a very good job of compressing jpegs so the data rate of
> the modem itself is all you are going to get (think of it as if
> compression wasnt even enabled)
>
> v92 supports max 56000(53333) down and max 48000 up (they realised
> that ppl actually -wanted- to upload) and the multimedia friendly v44
> compression (yes... it can compress jpeg data... think of v42 as .zip
> and v44 as bzip2 or rar)

This must be why we are finding used 56K v90 for $1 (one of the three 
actually worked at about 56K).  With people now switching to DSL, maybe a 
non-winmodem V92 will show upused.

Shrinking the jpegs helps more than compression.

> > > what are the model numbers of your modems? (sticker on the modem)
> >
> > One is internal, the other Sportster 0459.  Case says 1995, but they were
> > originally used with 14.4K modems.
>
> i find nothing on a model 0459 (does not exsist on the USR site)...
> what are the FCC ID numbers on the circuit boards? (since -- as i
> understand it -- you are using a different case for the external?)

The 0459 came in that case, I meant that the case was dated 1995 because 
they were first made then and used with 14.4K modems.
I may have read this wrong, upside down with a flashlight.  We have 
another similar one that came as V90 not X2.


> those 20sec freezeups are speedchange retrains.... if you use M2 you
> will hear a full retrain during those pauses...
>
> 14.4k is technically the most stable speed a POTS line can handle....
> anything faster is pushing the laws of physics...

If I dialed in at a slower speed would it freeze up less often?  For 
writing and reading email the speed is less important than a lack of 
freezeups.  I get freezeups even with a 33.6K modem, should I try 28.8K?

> > FTP downloads get progressively faster, to about 3K, and uploads get
> > slower, to about 3K.
>
> TCP/IP slow start (for downloads) and modem buffering (for uploads)...
> 3K is what you are stuck at it seems...

3.3K.  With a 33.6K modem.  3.1K with 56K - but variable.  Would a 33.6K 
speed actually upload faster overall, because of fewer freezeups?

Should I set connect speed to not 115200 but 57600 for 56K 1998 modems?

> >  I think the long wait at the end of kermit file
> > transfer (with Window Slots decreasing from 30 to 1) is when the modem
>
> ive never made any use of the kermit file transfer protocol... zmodem
> is the only thing ive used thats that old... and that was over a
> nullmodem cable.... i have no info/idea on how kermit would/should act
> over dialup...

> > buffer finishes unloading, and the 25K decreasing to 2K is because it is
> > getting data faster than it can send it.  Is there any advantage in
> > setting port (connect) speed with pppsetup to 115200 instead of 57600?
>
> should use 115200 with all modems.... that is unless they dont/wont
> support it (seems only very old 14.4k modems dont) need some room for
> compression to do its thing.... ever see a 14.4k modem do 6K/s? (AT&T
> paradyne.. commercial/business grade)...

I will check our 14.4K ATT (if I did not already recycle it).
Does anyone but Rockwell and USR make 56K internal hardware modems?

We had one external 56K Sportster that produced garbage at 152000, worked 
at 57600. Maybe broken somehow.  They keep working despite problems (such 
as taking the phone offhook as soon as you turnthem on, only running at 
slow speeds, needing to be told to go offhook before you dial....)
Lightning damage?

Thanks for all the helpful info.  Where did you learn so much about 
modems?

> > > > Sindi