SX212 random charecters

[panama800]

I tried my modem for the first time the other day on a BBS. It keeps on generating random characters. Any suggestions would be great thanks.

[+Nezgar]

Only when connected? Usually that's a sign of a noise on the line. Are you by chance running on a VOIP line? or maybe VOIP is being employed by your long distance provider, which might introduce noise, that may be more common and unavoidable these days. Unfortunately there's no built in hardware error correction in 1200bps modems...

[panama800]

im on a Comcast line.

[tep392]

I have the same problem. There's some discussion here.

 

http://atariage.com/forums/topic/266858-are-there-any-old-fashion-dial-up-bbss-left/?do=findComment&comment=3790249

[+DrVenkman]

Of course, the alternative to a modem is getting a Lantranix box or one of the newer wifi widgets that folks are making that plug into an RS-232 interface like a P:R:Connection or 850 module to bridge your existing home LAN to your Atari. From hte Atari's perspective, it's just another R: device.

[+Nezgar]

Comcast - cable provider right? If so, thy use a box to provide phone lines over cable... which is done over IP protocol... so it's not a 'real' analog circuit. The packetization introduces very small hiccups, pauses and delays that you may never hear for a voice call...

[+Nezgar]

Ironically, you may find that a faster modem works better on these digital voip lines. v.32bis (14400bps) and v.34 (28800+bps) protocols can be directly emulated by the cable/voip providers terminal adapters, so only the data is transferred over their private IP network, and the analog 'modulation' is only between your modem and the terminal adapter.

 

they also support the fax protocols, hence why people note fax works ok. I guess the cable/voip providers didn't see value in having their adapters emulate the older uncommonly used protocols anymore.

 

So basically, I expect best results would be had using a 14.4-56k modem on an 850 or PR connection (up to 9600bps even though modem may be connected at a faster rate)

 

That said, I do have some extra external US Robotics Courier 56K v.Everything modems... used one of these on my 8-Bit BBS until I shut it down around 2003. Best modems ever made IMHO. If you're interested in one cheap, for say $10? plus shipping from Canada.

Edited July 9, 2017 by Nezgar

[panama800]

Nezgar, I sent pm, thanks.

[+kheller2]

Sometimes you can adjust the voice quality. When i used Vonage services and needed modem support (Even for fast fax) I had to increase the quality of the VOIP.

[BillC]

Ironically, you may find that a faster modem works better on these digital voip lines. v.32bis (14400bps) and v.34 (28800+bps) protocols can be directly emulated by the cable/voip providers terminal adapters, so only the data is transferred over their private IP network, and the analog 'modulation' is only between your modem and the terminal adapter.

 

they also support the fax protocols, hence why people note fax works ok. I guess the cable/voip providers didn't see value in having their adapters emulate the older uncommonly used protocols anymore.

 

So basically, I expect best results would be had using a 14.4-56k modem on an 850 or PR connection (up to 9600bps even though modem may be connected at a faster rate)

 

That said, I do have some extra external US Robotics Courier 56K v.Everything modems... used one of these on my 8-Bit BBS until I shut it down around 2003. Best modems ever made IMHO. If you're interested in one cheap, for say $10? plus shipping from Canada.

In the early 90's I used to connect to CompuServe with a 14.4K modem, even with an MIO serial port configured to 19,200 BAUD I had to restrict the modem connection to 9,600 BAUD or lose characters because the MIO serial port didn't support hardware flow control.

 

So it would appear that the serial port speed needs to be twice as fast as the modem connection if hardware flow control isn't supported.

 

Len Spencer wrote serial port drivers for the MIO and Black Box that include flow control, but I have never tried them:

http://www.lenardspencer.com/Lenspencer/hyperspd.html

[+Nezgar]

Len Spencer wrote serial port drivers for the MIO and Black Box that include flow control, but I have never tried them:

http://www.lenardspencer.com/Lenspencer/hyperspd.html

 

Thats the one! You knew it was working because you could see the RTS/CTS lights on the modem toggling off and on, especially on outbound data. This was very important on my BBS with the MIO. if someone connected at 2400bps for instance, I would still be talking to the modem at 19,200, so obviously the modem needed a way to tell the computer when to pause sending, and when to resume.

[_The Doctor__]

and that helped the board sail along very fast... as drive access could continue while the other end was paused and your computer filled the sending modems' buffer.... so when the receiving modem was ready.. it was nearly instant with the data...