Baslinux mailing list

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

> > > > So why is the internal (slight newer) modem with the slightly older flash
> > > > taking longer to connect?
> > >
> > > multiple causes for this one;
> > >
> > > the modem is just trying to be more thourough in its check
> > >
> > > bad programming causing problems during the check
> > >
> > > corrosion on the pins in the jack causing noise or signal loss (make
> > > sure they are shiny)
> >
> > You mean the phone jack?  I can plug it in and out a few times.
>
> yes.. the phone jack in the modem... had (still have) a gateway 2000
> telepath 14.4k internal that had some serious issues till i took a
> flat-blade screwdriver and scratched it across the metal pins to get
> the corrosion off... worked perfect till i 'took it out of service'...
> replacing it with a rather flaky 33.6k (never did find out what was
> wrong with that one... wasnt connection problems but power-on
> problems... long story....)


> > > since its internal may be getting interference from a nearby card
> > > especially if it uses a transformer for phone line isolation (scsi is
> > > a bit noisy) or the PSU might be noisy (checked the modem in multiple
> > > systems?)  note: this one is rare but not unheard of...
> >
> > I have ISA SCSI card in that computer and this is an ISA modem.  (Are
> > there any pci hardware modems?).
>
> there are a few... but they use a different means (of course) to
> communicate rather than the standard UART... they need software to
> make them act like a regular com port in dos which isnt always the
> best at compatibility (but it does work) but performace of a hardware
> pci vs. isa is neglegable when used with OSs like linux or windows....
> when it comes to PCI modems tho buyer beware...
>
> > I try to put the modems as far as
> > possible from the power supplies.
>
> PSUs are sheilded in their own case... putting a modem close to one
> wont hurt.... what i ment by noisy was the power supplied by the
> PSU... an overloaded or tired (near the end of usefull life) PSU can
> make noise (low amounts of AC or even RF) on the normally pure DC
> power connectors... causing all kinds of random weirdness from modems
> not wanting to work properly to "hum bars" on the monitor to
> spontanious reboots

We had one power supply that interfered with radio reception upstairs ten 
feet away, and made it impossible to use a modem in the computer.

> putting the modem near a scsi card or video card thats particularly
> noisy (RF noise... usually from poor design) can cause interference
> with the modem....

So do I put the sound card in between scsi and modem?

> > > check your manual for an option for 'quick retrains' and make sure its
> > > turned on (if available)
> >
> > I will look online for this.  Just found a Supraexpress manual 28.8
> > AT+MS=? lists supported options
> > %CI MNP 5 enabled
> > %C2 V.42bis enabled
> > %C3 V.42bis and MNP 5 enabled (Default).
> >
> > They recommend turning OFF compression when transferred already-compressed
> > files such as ZIP, because it may actually go faster.  I will try it.
>
> make sure to only turn off compression and not error correction... (i
> made that mistake once... things went from slow to useless very
> quickly)

USR Sportster 14.4K manual (but my modem is 56K)
&K0 data compression disabled
&K1 auto enable/disable (default) - The modem enables compression if the 
serial port rate is fixed, and disables compression if the serial port 
rate follows the connection rate.  (Compression offers no throughput 
advantage when serial port and connection rates are equal, and may even 
degrade throughput).

&B1 - serial port rate fixed
&B0 - serial port rate follows connection rate
AT&F1 chooses defaults for USR and &B0 is the default, which means
compression is already disabled, but my enabling MNP halved the speed.
This must refer to V42.bis only.

&K2 Data compression enabled
&K3 Selective data compression.  disables MNP and uses V.42 bis only if 
the file is not already compressed.

I tried with the default (which is disabled compression) and with &K3 
(compress only if not already compressed) and ftp downloaded an .ogg file.
Default setting:  50 sec, 4061 cps
&K3 (checks to see whether to disable it):  60 sec, 3841 cps
My download speeds are rather variable anyway, from sdf, so this is within 
the margin of error.

I could do this test with a file which is not already compressed but I 
don't generally download large text files, just zip, jpg.

I could try &B1 fixed serial port rate and compression enabled.

The default is disabled compression.

> > %E   Do not request a retrain (default)
> > %E1  Monitor line quality and automatically request a retrain if line
> > conditions are bad.
> >
> > &K commands - flow control
>
> flow control should be set to hardware (in both the modem and your software)
It is the default.

> > Gateway Telepath 28.8 - supports full Hayes AT command set
> > Data compression:  V.42bis and MNP5 bps to 115,200 bps throughout.  Modem
> > also operates without data compression (maybe this would work better for 
> > jpegs?)
> > ATI 0-7
> > No %-type commands like the Supra.
> > &K0 - Data compression disabled
> > &K1 Auto enable/disable (default)
> > &K2 - Data compression enabled
> > &K3 - MNP5 compression disabled

Similar to the USR, less useful manual.

> > Obviously different modems use different commands.  I have a few USR
> > manuals around some place and will experiment.
>
> hayes standard is supposed to be universal (but its very simple...
> similar to the commands used with 9600 bps and less modems)

It was not universal for all the 14.4K or older.

> hayes extended is also supposed to be universal but quite a few
> manufacturers dont use it... newer USRs in particular.... zoom uses
> it....

> > But people around here have a choice and many still use dialup.
>
> well... keep an eye out then.... most anything dated 1998 and pretty
> much -everything- dated 1999+ will either be v92 or v92 flashable...

I will check ours for late 1998's.  I already flashed the 1997s X2s to V90 
with early 1998 files.

> > > also many newish hardware v90s are flashable to v92 (USR has linux
> > > flashers... might want to look into this one)
> >
> > Mine are 1997 and I already flashed them all.
>
> no newer flash updates available?
That was what I found for them, v90, dated early 1998.

> > A friend who thought his phone lines only supported 28K discovered he
> > could get 40K with a USB modem (after the onboard one died).
>
> i can get ~45k/s down its the upspeed i have problems with.... checked
> not to long ago to be at ~21k (always gets worse when the temperature
> cant make up its mind [frigid nights and hot days].. its just
> something ive come to be used to...)
>
>
> > I could try doing email online at a slower speed.
> > If I told it not to retrain what might happen?
>
> if things got bad the connection would instantly drop or become very
> unstable... (ive tried that one too)

Skip it.  I am satisfied with 3K/sec uploads, beats 1.5K.
> > Mine are not new.  I have a Hayes external that used to be 56K.
>
> used to be?

It is labelled 56K but downloads like a 28K.  I have two, the other worked 
as 56K until lightning struck. A USR 56K after the same lightning storm 
changed to 14.4K max.  Some day we may find the bad part, if people don't 
give us more old modems.
> > > a friend once asked (quite some time ago) if it would be possible to
> > > use a modem as an ad-hoc soundcard (play music through its speaker)...
> > > lines.... ever called anyone by using the hook switch to dial their
> > > number? ;) )
> >
> > No, how?
>
> pulse dialing... switch your phone to pulse and put the headset to
> your ear and dial your own phone number (so as not to bother anyone
> else)... if you have good rythm make a mental note of how the 'pop -
> pop - pop' noises are spaced... (the technical term for this is 'make
> and break ratio')... then... emulating the tempo of pulse dialing to
> the best of your abilities its possible to quickly tap the hook switch
> to dial phone numbers.... for instance tapping 5 times at the pulse
> tempo then waiting for the amount of time normally taken before the
> next number in the string is dialed then tapping 5 times again would
> dial the number "55"... tap once for 1, twice for 2, and so on... 0 is
> dialed using 10 taps... its very tedious but it does work... (expect
> to get a few "wrong numbers" and "this number cannot be completed as
> dialed" automated messages)

I guess we should not have thrown out the old dial phone that would no 
longer dial properly because the connections wore out, but used it this 
way.

How do you dial a bbs without a terminal program, echo atdt1234567 > 
/dev/ttyS1, etc.?