🚀 go-pugleaf

In article <820709627snx@holly.demon.co.uk>, Mark Rogers
<mcr@holly.demon.co.uk> writes
>I have now found what I think is the Zoom manual, so that the differences 
>between the two INIT strings can be determined.
>
>AT&F (set factory defaults) expands to:
> AT B1E1F0L1M1N1Q0V1W0X4Y0 &C0&D0&G0&K3&P&Q5&S0&T4&Y0 %C3%E0 \A1\G0\L0

How do you work this out?  It is dificult to be sure what the state of
the modem is without the S-Registers, particularly as \N is missing.

Could you please post the output of say AT&F0&V.  Thanks.

>
>AT&F0 is equivalent to AT&F. We can remove any redundant parameter 
>setting:
>
>Therefore, AT&F0E1N0Q0X3Y0&C0&D2&G2&J0&K3&R1&S1&T4S37=11 (Failed) =
> AT &F N0X3 &D2&G2&J0&R1&S1 S37=11
>
>Similarly, AT&F0W1&C1&D2%C2 (Worked) =
> AT &F W1 &C1&D2 %C2
>
>&D2 is common to both, so can't be an issue, but only means "hang up if 
>DTR dropped" anyway.
>
>Of the remaining commands:
> (the following from the FAILED init string)
> N0S37=11  - Force 14k4 V.32bis connect
> X3        - Affects which modem responses are displayed

X3 also enables blind dialing ( I.e. dialing regardless of whether there
is a dial tone.  Presumably, you do know you are dialing the right
number, i.e. ringing and then a carrier.

> &G2       - Enable 1800Hz guard tone
> &J0       - Not defined in manual

&J0 selects the RJ11 telephone jack, it is the default.  &J1 is included
only for Hayes cmpatibility and performs no function.

> &R1       - Not defined in manual

&R1 affects the operation of the CTS control signal.  Descriptions of
this command vary wildly.  I suspect that the effect of the command does
not vary much, only the descriptions ;-).  &R1 forces CTS true in
syncronous mode and will only drop in asynchronous if required by
hardware flow control.  &R0 would cause CTS to follow RTS in
synchronoush mode and act according to the V.25bis handshake in
asynchronous.  I always use &R1, because it is the only description I
understand!  

> &S1       - DSR active after answer tone detected, inactive after 
>             carrier loss
> (the following from the WORKING init string)
> W1        - Affects which modem speed/protocol parameters are reported
> &C1       - RLSD (DCD) follows remote carrier
> %C2       - Enable V.42bis compression (note: default is V.42bis *and* 
>             MNP5 both enabled)
>
>The two un-defined parameters are interesting (&J and &R), as is the fact 
>that the failing INIT string appears to accept the default of V.42bis 
>*and* MNP5 enabled.
>
>I will do some more experiments this evening to try and determine which 
>parameters are valid, but I repeat that both strings work with the USRs. 
>I have also just checked and can confirm that both are indeed from 
>MODEM.TXT. I have included the detail of my "workings" here to prompt 
>others to experiment, although I would suggest that in most cases the 
>level of detail included here need not be posted (although any 
>conclusions should be). 
>
>Mark.

Could you please describe the characteristics of the working and failing
connections.  Are the working connections V.42 (error detecting), are
they V.42bis (data compressing).  Do the failed connections get an
answer, do they start to handshake, is there a connected message, do
they get a login prompt?

I hope this helps.
 Dave
-- 
Dave English, T U R N P I K E  Ltd
250/256 High Street, DORKING, Surrey, UK. RH4 1QT
My other computer's a brain