Author Topic: Using a dial-up BBS over an Obi200/Google voice box  (Read 14977 times)

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Offline AmperaTopic starter

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Using a dial-up BBS over an Obi200/Google voice box
« on: December 26, 2017, 01:06:08 am »
Today, with many landlines being shut down or converted to DSL dry runs, it's nearly impossible in a lot of areas to connect to old BBSes that are still around like the Back To The Future BBS.

So, I had an idea. Obihai sells boxes like the Obi200 that you can link up to a google voice account. The issue with most VOIP services is their use of lossy encoding, and while I can't exactly speak for Google Voice, Obihai supposedly states that their Obi200 boxes support faxing, which is as we all know, just a modem.

So what about results. Originally my test system was my Pentium Pro 200Mhz machine, but due to probably DMA or IRQ issues, I'm not sure what, other devices directly interfered with the signal.
After a quick bout with my 486, I settled on my Pentium 3 450mhz Slot 1 machine.

Now, I am new to BBSes, having never used one in my life, so my experience with terminal programs is rather lacking. I was using Hyperterm as it was easy to get, being already included on Windows. Now right out the gate I do not think this is an amazing option. I had crashes, and I had the program refuse to work or update any settings. Perhaps another terminal would be nicer.

I was using the BTTF BBS at 978-822-2586. First try I think I was using either 4800 or 9600 baud, and it worked! The characters rolled in, and I was asked to login. Here's where the no to unforeseeable issues happened.

Of course the terminal was getting garbage characters in and out every few moments. Now, before you call compression on me, this could be for any number of reasons. My settings could be off, and hyperterminal could just not be all that great. Either way, I am still working on this. I decided to post this as I thought it would interest some people, and if I can get this working reliably, it would make for a very neat and cheap way to hook into a BBS without a landline.

There are potentially other VOIP services that may work better, as the Obi boxes, to my knowledge, are not limited to Google Voice. Any suggestions are welcome, but keep in mind that the question "Why would I even want to do this" is one answered by "because I can".
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Offline Bruce Abbott

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #1 on: December 26, 2017, 06:23:32 pm »
Obi200 boxes support faxing,
...via T.38 protocol.

the job of T.38 is to “fool” the terminal into “thinking” that it’s communicating directly with another T.30 terminal. It will also correct for network delays with so-called spoofing techniques, and missing or delayed packets with fax-aware buffer-management techniques.

Spoofing refers to the logic implemented in the protocol engine of a T.38 relay that modifies the protocol commands and responses on the TDM side to keep network delays on the IP side from causing the transaction to fail. This is done, for example, by padding image lines or deliberately causing a message to be re-transmitted to render network delays transparent to the sending/receiving fax terminals.

 

Offline coppice

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #2 on: December 26, 2017, 07:22:44 pm »
Traditional PSTN modems hardly ever work over a VoIP channel. If you get a G.711 channel from end to end you've solved one problem (I assume this is what you are thinking of as the converse of having lossy codecs, but the G.711 codecs are also lossy/compressed. However,  these are the codecs which the PSTN modems were designed to tolerate). A bigger problem, however, is timing. Very few VoIP channels make any effort to synchronise the clocks at the two ends of the link. If the buffer at the receive end starts to underflow, some fudging is used to fill in the gaps. If the buffer at the receive end starts to overflow, some fudging is used to throw away some samples in the least audible manner. There may also be silence compression, and other manipulations, even when the codec is one of the G.711 ones. Either way, modems cannot tolerate this dynamic manipulation of time. They were designed for a world in which the PSTN has enough rubidium clocks to keep the entire end to end path in lock step.

There is a series of ITU specs - V.150, V.151, V.152 - designed to support modems over VoIP paths, in a similar manner to how T.38 supports FAX over VoIP paths. They put a modem at each end of the VoIP path, and translate between audio and pure data. While T.38 has been widely deployed, the V.15x series specs have seen very limited deployment.

You may have heard of FAX and modem signals being carried reliably over VoIP links run end to end by PSTN operators, using G.711. They are using carefully groomed channels, with rubidium clocks at each end. This is not something a consumer can generally replicate.
 

Offline rrinker

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #3 on: December 26, 2017, 09:14:28 pm »
 I wonder if the old OPUS software I used to run is still around somewhere? That was a very powerful yet easy to set up BBS system, quite fast on the message threads, too.
 This being back in the 1986-1988 time frame, having a 2400 bps modem was a huge luxury, but we had an on-campus datanet with a serial port in each room, nominal speed was 9600bpbs but someone got the specs from the system manufacturer and found out it could actually do 19200bps, so a bunch of us petitioned the Telecom department and they upgrades use to get the full 19200. One of my friends who helped run the BBS is highly artistic so he drew these amazing ANSI graphics art files, and even animated a few. At 19200, it was very smooth, still usable at 9600, but as off-campus access was through a bank of 1200bps modems, it was unusable for outside callers - but simply hitting a key stopped the animation and went to the next page. I wish I still had copies of this somewhere. Since the name of the software was OPUS (nothing to do with the penguin), we of course went with a Bloom County theme for the BBS. Called it Starchair Enterpoop. The logon animation started with Opus and Milo and couple of other characters standing in Milo's Meadow and then a Star Trek style transporter beam materializing them on the bridge of the ship. Logoff sequence showed the tail end of the Enterprise, the shuttle bay doors would open, and the Basselope would fly out and zoom past.

 

Offline Halcyon

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #4 on: December 27, 2017, 01:05:29 am »
I'm doing things slightly differently, rather than my old computers dialing a PSTN service, I'll be using a device which essentially connects my old machines via a serial port to my Wi-Fi network and connecting to the BBS via IP.

This product might be of interest to you (although it's currently out of stock): http://biosrhythm.com/?page_id=1453

All the old machine sees is a Hayes compatible modem.
 

Offline AmperaTopic starter

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #5 on: December 27, 2017, 02:36:01 am »
It would be nice to do this over the telephone. I might try to find someone with a known working modem and try to communicate with them just to see if I can get my settings right.

It just very very nearly works, and I want to be sure that I can't do anything to it through configuring to get it to work.
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Offline Halcyon

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #6 on: December 27, 2017, 02:50:06 am »
The other thing I thought about doing was running my own PSTN emulator which dialed a modem sitting in my own server. From there, use a proxy to forward IP packets to/from my old gear. Yes, it would be nice to keep the old tech all the way through, but these days, it's becoming less and less viable. I get great joy getting my old gear to work with modern equipment, for example, connecting my C64 to my LAN then out to the internet.
 

Offline Bruce Abbott

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #7 on: December 27, 2017, 07:24:48 am »
I get great joy getting my old gear to work with modern equipment, for example, connecting my C64 to my LAN then out to the internet.
Which is what we would have done back then, if the option was available. My external modem went in the bin as soon as I figured out how to connect my Amigas to the Internet via a PC.

Quote
The other thing I thought about doing was running my own PSTN emulator which dialed a modem sitting in my own server.
I have been thinking about this too. I have a number of old PCs with (otherwise useless) modem cards installed. Could install BBS software on one, and plug the modem into my (otherwise useless) internal phone wiring. Then relive the 'good old days' of downloading stuff from a BBS - without having to wait for a free line! 

A full PSTN emulator would be neat, but probably not necessary. I am thinking 12~24VDC for loop detection and line current, basic DTMF detection to tell when a number is being dialed, and dial/ringing tones generated at the appropriate times - all controlled by a small MCU. Might also need a ringing generator to trip the PC modem's ring detect. Ringing voltage can be generated by an audio power amp driving a small mains transformer wired backwards - or perhaps just use raw 24VAC at mains frequency (since the PC modem probably won't mind if the ringing frequency is a bit higher than normal).
   
 

Offline Halcyon

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #8 on: December 27, 2017, 09:09:29 am »
These also just became available a few days ago: https://www.cbmstuff.com/proddetail.php?prod=WiModem232OLED

Available with or without OLED display.
 

Offline Hawke

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #9 on: January 02, 2018, 11:50:02 pm »
HyperTerminal cannot correctly display ANSI codes and often showed control characters when connecting to a DOS BBS. If you can find a copy of Terminator by Bo Bendstien it was one of the better dialling programs with a ton of modes and emulation types, I do have it here on a Nightowl CD somewhere and could probably find it. Going one step further Wildcat 5 came out with a windows dialling that could connect to DOS and display the right codes but it also allowed you to connect to a BBS over the internet. Wildcat 5 was released into the public domain by the company that made it as the internet killed the business. It is a complete BBS system that allows you to have both ANSI screens and windows screens and DOS connectivity via the internet. It runs on Win95 upto Win98SE but I may have had it running on XP as well. As for DOS version I have all of them including manuals and compilers for making custom parts or plugins they called them for the lower Wildcat Versions. I ran a Wildcat BBS with ten lines from about 1993 to 1999 and had tried many other types of BBS software. Nothing really compared to Wildcat and it looked great. I had 40 CD drives in different towers which I still have in my shed and updated the CDs every three months or burned new ones from things I had downloaded from the net. It could multi task like  a boss for the hardware it all ran on. Terminator is DOS only if you are going the DOS route. From memory Wildcat cost around $300.00 back then and you had to buy each update or new version at a lower cost. It wasn't cheap to run a  BBS with constant hardware upgrades, phone lines which made long distance calls to retrieve its FIDO net NODE packets every night but it was great fun. I,m sure the DOS versions of Wildcat aren't protected anymore so parting with a copy if the floppies are still good wouldn't be a problem either. Cheers
 

Offline james_s

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #10 on: January 10, 2018, 06:19:32 am »
I always used Crosstalk Communicator under DOS for BBS's. https://archive.org/details/CrosstalkCommunicatorTerminalEmulator

I've never been able to get a modem to work over a VOIP line but there may be some that will support it. Lots of fond memories of staying up half the night messing around on those, I sure don't miss having someone pick up the extension phone during the last 2 minutes of a 5 hour download though.
 

Offline timb

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Using a dial-up BBS over an Obi200/Google voice box
« Reply #11 on: January 10, 2018, 09:26:04 am »
I get great joy getting my old gear to work with modern equipment, for example, connecting my C64 to my LAN then out to the internet.
Which is what we would have done back then, if the option was available. My external modem went in the bin as soon as I figured out how to connect my Amigas to the Internet via a PC.

Quote
The other thing I thought about doing was running my own PSTN emulator which dialed a modem sitting in my own server.
I have been thinking about this too. I have a number of old PCs with (otherwise useless) modem cards installed. Could install BBS software on one, and plug the modem into my (otherwise useless) internal phone wiring. Then relive the 'good old days' of downloading stuff from a BBS - without having to wait for a free line! 

A full PSTN emulator would be neat, but probably not necessary. I am thinking 12~24VDC for loop detection and line current, basic DTMF detection to tell when a number is being dialed, and dial/ringing tones generated at the appropriate times - all controlled by a small MCU. Might also need a ringing generator to trip the PC modem's ring detect. Ringing voltage can be generated by an audio power amp driving a small mains transformer wired backwards - or perhaps just use raw 24VAC at mains frequency (since the PC modem probably won't mind if the ringing frequency is a bit higher than normal).
   

You don’t really need to do any of that. There’s various bits of open source software that can emulate the AT command set and fool software into thinking its talking to a modem, then the data is forwarded over IP to the destination.

So, your setup would be like this:

Old Computer’s Serial Port -> Null Modem Cable -> Modern Computer/Raspberry Pi -> Internet -> BBS via Telnet

One piece of software for emulating the AT command set is called ATduck and works reasonably well. Essentially, in your DOS/Windows terminal software (ProComm Plus, BananaComm, Etc.) you substitute the remote BBS’s IP for the phone number (ATDT 192000001100 to connect to 192.0.1.100).

ATduck can also be combined with a SLIP or PPP daemon, thus emulating a dialup ISP and allowing you to easily connect an old system to the internet (or just your LAN) through WinSock or a DOS PPP packet driver, all without needing a network card in the PC!

I’ve got a BeagleBone Black setup as a Retro Computing router using this method and it works great. I’ve got a Libretto 70CT connected wirelessly via Serial IR and a Compaq Portable III via normal wired serial.

I setup the software on the BBB to directly route data via telnet when it receives an ATDP dial command and to launch the PPP daemon on a ATDT dial command. That makes it easy to configure different applications on the retro machines without changing anything on the BBB.

Anyway, pretty much every BBS still running today provides access over Telnet. So that’s the way to go IMHO. (There are also DOS Telnet clients available that you could use to directly access the BBS via a packet driver, but they’re not quite as advanced as various communications packages from the era, in terms of displaying special ANSI sequences and stuff, hence the reason to emulate a modem with ATduck.)
« Last Edit: January 10, 2018, 09:29:01 am by timb »
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Offline AmperaTopic starter

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #12 on: January 10, 2018, 04:59:13 pm »
That's not the fun way to go though. Using an Obi box is kinda a stretch enough. The idea is to have it work just like a phone line.

Anyways, I unfortunately have not gotten farther, but I have not attempted to. My Pentium 3 is a bit iffy on all of this with the software, my Pentium Pro has some strange interference issues with the modem and other cards (even on different IRQs) and my 486 refuses to detect the CD drive when I use a 2.5GB HDD instead of a 2.1GB one, a problem I've never had before.

I currently have a laptop with a built-in modem I am trying to get working with it. Hopefully that yields some success.
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Offline james_s

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #13 on: January 10, 2018, 06:02:08 pm »
I'm not surprised the 486 doesn't work with a 2.5GB hard drive, many PCs of that era won't support anything larger than 512MB, hence the various overlay programs that were available once drives of that size appeared. IIRC 2GB is another barrier that some older systems couldn't go beyond.
 

Offline AmperaTopic starter

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #14 on: January 10, 2018, 06:43:32 pm »
I'm not surprised the 486 doesn't work with a 2.5GB hard drive, many PCs of that era won't support anything larger than 512MB, hence the various overlay programs that were available once drives of that size appeared. IIRC 2GB is another barrier that some older systems couldn't go beyond.

That 486 can LBA up to 8GB drives, and can use FAT16 with all that space, it just needs four partitions. The issue is down to the oak CD-ROM drivers not detecting a CD on any controller or connector with just that drive in there even though it worked fine before. Even when I set the drive to limit itself to 2.1GB, making it virtually indistinguishable from my other hard drive by use of a special jumper configuration, it still didn't work at all.

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Offline timb

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #15 on: January 11, 2018, 05:51:26 am »
That's not the fun way to go though. Using an Obi box is kinda a stretch enough. The idea is to have it work just like a phone line.

Using ATduck or similar software makes it work just as if you have an external serial modem attached to the serial port. If you’re trying to get your old system to talk to a BBS or even a server in your house, I don’t see why you wouldn’t do it this way...

You’re going to have a very hard (if not impossible) time directly connecting two modems together (by that I mean wiring them directly together, Modem <—> Modem). Now, if you have a small analog PBX system in your house, it would work fine (the PBX would act like the Central Office’s switching gear, providing the required on and off hook voltages the modems expect).

So, unless you already have a PBX (or equivalent) system in your house, setting one up just to connect to a computer in the next room seems like a ton more work compared to setting up software on a Raspberry Pi to simulate a serial modem! (And you really only need to do that if the DOS software you want to use only supports modems (I.E., isn’t TCP/IP aware); for Packet Driver aware DOS software and WinSock aware Windows software, you can bypass the modem emulation and simply have the Pi act as a CSLIP or PPP server.
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Offline Halcyon

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #16 on: January 11, 2018, 06:49:54 am »
That's not the fun way to go though. Using an Obi box is kinda a stretch enough. The idea is to have it work just like a phone line.

Using ATduck or similar software makes it work just as if you have an external serial modem attached to the serial port. If you’re trying to get your old system to talk to a BBS or even a server in your house, I don’t see why you wouldn’t do it this way...

You’re going to have a very hard (if not impossible) time directly connecting two modems together (by that I mean wiring them directly together, Modem <—> Modem). Now, if you have a small analog PBX system in your house, it would work fine (the PBX would act like the Central Office’s switching gear, providing the required on and off hook voltages the modems expect).

So, unless you already have a PBX (or equivalent) system in your house, setting one up just to connect to a computer in the next room seems like a ton more work compared to setting up software on a Raspberry Pi to simulate a serial modem! (And you really only need to do that if the DOS software you want to use only supports modems (I.E., isn’t TCP/IP aware); for Packet Driver aware DOS software and WinSock aware Windows software, you can bypass the modem emulation and simply have the Pi act as a CSLIP or PPP server.

THESE were pretty popular in Australia but bloody expensive for what they are.

I do recall seeing someone building one and providing schematics on the internet, but that was years ago. You'd be able to Google it. Two modems just connected together won't do anything.
« Last Edit: January 11, 2018, 06:51:56 am by Halcyon »
 

Offline AmperaTopic starter

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #17 on: January 11, 2018, 01:59:49 pm »
The idea isn't to connect two modems in the same room. The idea is to simulate an actual POTS line that goes out to the real world on what could be best described as the Bell system using regular telephone numbers, and then to connect to a real BBS that still has a modem to connect to. Even 300 baud would be fast enough to get text in and out for a BBS.
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Offline Bruce Abbott

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #18 on: January 11, 2018, 06:08:44 pm »
You don’t really need to do any of that.
I don't need to do any of that, but I want to recreate the experience of using a dial-up modem - including hearing the tones it produces as it connects. For the most authentic retro-computing experience, I want to use real vintage hardware wherever practicable, including the modem.

The idea of connecting to a BBS via Telnet is interesting, but I don't want to be tied to a power-hogging modern PC (and certainly not a Raspberry Pi, which I don't own and never will). I have a few old PCs with internal modems and network cards that should be suitable. I now also have wireless Internet, so I am thinking an ESP8266 might do it (combined with the telephone line interface and an old 14400 external modem that I have).

Quote from: Halcyon
Two modems just connected together won't do anything.
True, but they can be made to talk to each other if you just supply some line voltage. The only problem is without ringing voltage you have to tell the receiving modem to answer the call.
 
 

Offline cdev

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #19 on: January 11, 2018, 06:21:14 pm »
Some time ago Motorola made a SIP device (the VT1005 I think) that was quite good and also understood the rotary dialing of an old analog phone.

So if you have one you can use an old mechanical dial phone, the kind with the physical bell inside (!)  for VOIP.

Why not go for the entire retro experience?
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Offline AmperaTopic starter

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #20 on: January 11, 2018, 06:56:47 pm »
gotta use an acoustic coupler for full effect.
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Offline timb

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Using a dial-up BBS over an Obi200/Google voice box
« Reply #21 on: January 12, 2018, 03:56:42 am »
You don’t really need to do any of that.
I don't need to do any of that, but I want to recreate the experience of using a dial-up modem - including hearing the tones it produces as it connects. For the most authentic retro-computing experience, I want to use real vintage hardware wherever practicable, including the modem.

The idea of connecting to a BBS via Telnet is interesting, but I don't want to be tied to a power-hogging modern PC (and certainly not a Raspberry Pi, which I don't own and never will). I have a few old PCs with internal modems and network cards that should be suitable. I now also have wireless Internet, so I am thinking an ESP8266 might do it (combined with the telephone line interface and an old 14400 external modem that I have).

Quote from: Halcyon
Two modems just connected together won't do anything.
True, but they can be made to talk to each other if you just supply some line voltage. The only problem is without ringing voltage you have to tell the receiving modem to answer the call.
 

I don’t understand what you plan to do with the ESP8266 and a external modem. Can you elaborate a bit?

If your vintage PCs already have network cards you can connect to a BBS via Telnet without “power hogging modern PCs” (which are actually a lot more efficient per MHz/Watt than a vintage system, by the way) in DOS or Windows directly.

Under DOS, simply download the appropriate Packet Driver for your network card (or use a NDIS shim) and a suitable Telnet application (there’s one included in the wonderful MTCP package). Under Windows 95/98 you can use HyperTerminal or even PuTTY (v0.61 is the last to run on 9x IIRC) for Telnet access.

I have a beautiful Compaq Portable III (286) system hooked to my network via an ISA based 3Com EtherLink III and it works great! It runs FreeDOS 1.2 now off a 1GB CF card. (Up to last year it was running MS-DOS 6.22 off the original 40MB IDE hard drive from 1987 and had network connectivity via the aforementioned BeagleBone Black Modem Emulator.)

I ended up installing the network card when I replaced the HDD with CF because I needed somewhere to plug in a XTIDE ROM (it’s an open source option ROM designed for PC XT and AT class machines, which gives them access to drives over 500MB; my Portable III was one of the first machines released with an IDE interface and the native BIOS only gives you a choice of about 20 drive types with no custom option). XTIDE also allows you to boot or access floppy and hard disk images hosted from a modern machine over a serial link (they show up as a physical B: or D: drive to DOS) hosted from a modern Windows machine running a console application, which is very handy, especially considering this machine only has a 5.25” drive.

Anyway, I have a NI GPIB card in the second ISA slot and use the system as a bridge to communicate with some older test gear I have. It logs data to a text file and runs an FTP Server TSR in the background, which a modern machine uses to pickup and process the data with. (Yes, I could modernize it with a USB GPIB adapter hooked directly to the modern system, but I love watching waveforms show up and data scroll by on the soothing orange plasma display. It warms the cockles of my heart.)
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Offline timb

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #22 on: January 12, 2018, 11:50:46 pm »
@TwoOfFive-TertiaryAdjunctToUnimatrixZero:

I came across this today while searching for something modem related. He was able to establish V.90 (56k) connections over VOIP to a local ISP. He also got V.92 connections going, from Australia to the US (!!!) no less.

He uses a Linksys Analog Telephone Adapter and routes the calls through a local Asterisks Server onto a VOIP provider. Apparently using the Linksys ATA is the key, as he can completely turn off VOIP echo cancellation (modems rely on the echo being there), set jitter and delay to fixed values and force using a specific codec.

(You wouldn’t need a local Asterisks Server; he only used that so he could easily record raw PCM wave files of the modem handshakes, for archival purposes, using WireShark.)

Anyway, I’d guess you need a highly configurable ATA and a VOIP provider that supports a good enough codec, but it looks doable.
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Offline AmperaTopic starter

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #23 on: January 13, 2018, 04:59:43 am »
That was the idea with the Obi200 box, however it has a quite extensive arrangement of settings, so I wonder if I can't disable echo cancellation somewhere in there and get better results.
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Offline cdev

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Re: Using a dial-up BBS over an Obi200/Google voice box
« Reply #24 on: January 13, 2018, 05:16:03 am »
Ive sent fax successfully using a VOIP box.. using an old inline ADSL filter/ RFI noise suppressor slowed down the handshake and proved to be just the ticket...
« Last Edit: January 13, 2018, 02:10:58 pm by cdev »
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