I found this interesting since I worked for Modem Maker Racal-Vadac in the 90's. We designed a POTS simulator in 1 box that was about 18" by 18". It had switches on the front along with a display, so you could enter in the number for each phone you were testing, and to make a call to either phone, from either phone. You could also simulate, Busy, Re-Order etc. It also had the facility to connect Modems to it as well so you could test those as well. Last feature had jacks to plug 2 Computers into it as well; with the feature to run it as a bulletin Board, (BBS). Those were the days!
First of all, how could we not be showing love to that? Martin Scorsese-esque introduction!?!? I've said it 100 times but this project is ridiculous and I love every bit of it. Pretty big fan of those two computers also 🙂
The best thing about completing the project is the instant justification for hanging onto all of that so-called obsolete stuff for decades. nostalgia is never obsolete.
Brings back old memories of spending hours on various bbs in the early 80’s. Miss that modem negotiation tone. Thanks! Oh I still have a 56k US robotics courier, the really good black version.
My Ex ( and I state "EX" ) took all my old modems, computers and a heep of other prized possessions to the dump so she could install a shoe rack in the big closet. I still have her shoe rack.
@@Wranorn The really old days. The earliest modem use was over my friend’s house. His father had a commodore PET with an acoustic modem. Take the handset off the phone and place it on the modem. I had no idea what this was at the time.
I'm a field tech and work on analog phone systems,... I've been looking at something to replace a Viking DLE-200B and I think this is the closest I've come,.. (I want to build something using Dial tone and DTMF tones for control signals, and this is a great start)
This is awesome. I've just ordered the PCBs and a bunch of parts to assemble some. I wish i'd watched the video a bit closer and realised that the phone signal isn't being sent by Wi-Fi between the boards. But still, I will be having lots of fun with this project and I will likely see if I can find a way to encode the audio signal between the modules using some lossless protocols and have WIFI enabled connectivity. I need to research compression protocols that support data sessions (im sure there are some) that I can use for that. I feel like I've fallen down the rabbit hole. :P
there is another project with a goal of trying to get everything working wirelessly although it isn’t working yet but it might be a future resource. It’s the project where I got the pulse dialling function from github.com/ktownsend-personal/RetroPhone
Your experimentation seems to be turning into a well developed product. Have you thought of doing a small production run of assembled kit and listing them on ebay? For us less adventurous crowd who finds the thought of ordering our own kits from PCBW to deep a rabbit hole? Lorne.
20 or 25 years ago I used to sometimes sell things including on eBay that I made but it’s gotten to a point where it’s a complete hassle for small sellers between shipping costs and parts and labour and having to deal with any problems that come up so I find it easier to just provide the information from my own hobby stuff and people can replicate
This is really Great! have you got these working with more than 2 endpoints? I've been looking at something like this for my kids to play with, with their friends.
It's hard to find out because some items I had to get on AliExpress (or maybe ebay has the same options) like the phone SLIC module, and I also got the ESP32, RGB LED and MT8870 DTMF chip on Ali. Also I think the MT8870 may be officially obsolete now so some obscure places may have stock when searched on Octopart but of course Ali has them. Looking up what Mouser does stock and then glancing at the rest on Aliexpress, I estimate $30USD in parts aside from the bare PCB, but if buying from scratch on Ali it would be higher because for example you'd buy a set of 10 MT8870 chips for maybe $5, so I counted the per unit as maybe 50 cents for the BOM.
If you can remove the trunk line wire and make it Wireless or work on a local or wide area network work over the internet it can make a lot of money cuz I've been looking for something like this without having to install a PBX system
This is really cool. I've wanted to do something like this myself for a very long time. Have you considered the possibility of running some sort of terminal server on one side of the connection, whose behaviour could be influenced by the operation of the Phone SLIMs state. For example, certain dialled numbers could command the terminal server to connect to a telnet-accessible BBS on answer instead of a local one, altering the baud rate of its modem at the same time. It could also simulate randomised busy signals via modem off-hook etc
The project can go in many directions and so far I’m working on various local hardware infrastructure ideas so I’m only looking at connecting physical devices wired together. There’s another project out there that might go more toward network access so over time a bunch of capabilities may exist between multiple projects. The next thing I’m working on is a multi node server type hub where multiple SLIM boards have their phone cable plugged into a port on it and wirelessly communicate to that to coordinate calls instead of going node to node directly like now. So if there are four separate SLIM nodes plugged into the hub, when a call is being placed it will be wirelessly communicate to the hub which will determine if the call can be routed or not and then complete the connection path or notify the node of the busy status so it can generate the busy signal on that line. In that multi node set up one of the nodes could be some sort of terminal interface bridge thing where other nodes can dial that one to do specialized things instead of regular calling to the other nodes. I’m trying to gradually expand it and keep it modular so things can be changed or reconfigured and expanded as ideas come up.
@@GadgetReboot All understood. It's a great project with many possible applications. I look forward to seeing the hub concept as it comes to fruition. I'll try and make some SLIM nodes for myself - I have a bunch of old ex-Telecom Australia rotary dial phones that could benefit from them!
I have uploaded a video to youtube. For some reason, the option to view the transcript of the video does not exist. It does not appear automatically on the right side of the window and the option to view the transcript does not appear. In other words, when I click on the button with the three dots "...", the option to view the transcript is not there. Please advise. Part of the very reason for me to make this compilation video and upload it was to be able to view the transcript. Please help or offer advice. I can not find an option to view the transcription of this video either. Is it a setting of the video maker or a setting with my account?
Hi, nice video. So if I understood, a BBS server should have one phone line for every user connected at the same time? Or it was just not possible to have more than 1 user? I was playing around with PCs (and even programming games) in the eighties but I didn't have a modem until after Internet was a thing.
That is correct. Most hobby BBS's were a single remote user only (the operator could chat from the console). Also, while these BBS's were in networking mode, exchanging messages with each other, no other users could connect. Fun fact: the zmodem protocol was created to cut the length of networking calls between BBS's, as a few boards made long-distance connections and thus the 'calling' system was charged long-distance rates per minute. Instead of just batching up raw messages and transferring them uncompressed with xmodem, zmodem would ZIP the files prior to transfer, and unzip them on receipt. Since most of the transferred files were raw text, compression was very effective at cutting transfer times.
Yes, one per caller, I built one using an 8 port digiboard in the early 90’s and had 8 phone lines to it. Eventually you could have a T-1 (ISDN PRI) with 24 lines broken out and a hunt group phone number in front of all of them. Companies made modem banks, rack mounted, that connected V.35 over to the line interface.
for now it was only designed for two boards but it’s possible that instead of plugging the extra phone line directly from one to another, each board could plug into another sort of switching board where nodes could be routed together as needed or else if it could be evolved into completely wireless without the need for the extra hard line, data packets could just go wherever needed so it may be something that could happen later if there’s any interest in developing this.
probably the maximum normally achievable because I think it’s all just analog tone signalling so as long as the signal integrity on the phone line is noise free, which I would expect on a bench test set up then it should be fine. I was connecting at 33.6 K and I think the fastest even possible is 56K for standard dial up modems but I can’t remember all of the details.
![PASULOL รามเกียรติ์ ตอนที่ 4 นนทกพบรัก [Ramakien Ep.4: Nonthok in love]](http://i.ytimg.com/vi/tMUQgmZzf_A/mqdefault.jpg)
![เจ็บที่ยังฮัก - ม่อน วรวิทย์ [ Official Mv ] จอนนี่มิวสิค](http://i.ytimg.com/vi/KALIGSRSjFs/mqdefault.jpg)
I found this interesting since I worked for Modem Maker Racal-Vadac in the 90's. We designed a POTS simulator in 1 box that was about 18" by 18". It had switches on the front along with a display, so you could enter in the number for each phone you were testing, and to make a call to either phone, from either phone. You could also simulate, Busy, Re-Order etc. It also had the facility to connect Modems to it as well so you could test those as well. Last feature had jacks to plug 2 Computers into it as well; with the feature to run it as a bulletin Board, (BBS). Those were the days!
First of all, how could we not be showing love to that? Martin Scorsese-esque introduction!?!?
I've said it 100 times but this project is ridiculous and I love every bit of it. Pretty big fan of those two computers also 🙂
The best thing about completing the project is the instant justification for hanging onto all of that so-called obsolete stuff for decades. nostalgia is never obsolete.
Brings back old memories of spending hours on various bbs in the early 80’s. Miss that modem negotiation tone. Thanks! Oh I still have a 56k US robotics courier, the really good black version.
My Ex ( and I state "EX" ) took all my old modems, computers and a heep of other prized possessions to the dump so she could install a shoe rack in the big closet. I still have her shoe rack.
I used to use a 300 BPS Modem Cartridge on a TRS-80 CoCo I,.... BLAZING SPEEDS
@@Wranorn
The really old days. The earliest modem use was over my friend’s house. His father had a commodore PET with an acoustic modem. Take the handset off the phone and place it on the modem. I had no idea what this was at the time.
I'm a field tech and work on analog phone systems,... I've been looking at something to replace a Viking DLE-200B and I think this is the closest I've come,.. (I want to build something using Dial tone and DTMF tones for control signals, and this is a great start)
This is awesome. I've just ordered the PCBs and a bunch of parts to assemble some. I wish i'd watched the video a bit closer and realised that the phone signal isn't being sent by Wi-Fi between the boards. But still, I will be having lots of fun with this project and I will likely see if I can find a way to encode the audio signal between the modules using some lossless protocols and have WIFI enabled connectivity. I need to research compression protocols that support data sessions (im sure there are some) that I can use for that.
I feel like I've fallen down the rabbit hole. :P
there is another project with a goal of trying to get everything working wirelessly although it isn’t working yet but it might be a future resource. It’s the project where I got the pulse dialling function from
github.com/ktownsend-personal/RetroPhone
This is amazing BT just killed our analog phone service, but this would be great for building postcode/building level phone networks
Your experimentation seems to be turning into a well developed product. Have you thought of doing a small production run of assembled kit and listing them on ebay? For us less adventurous crowd who finds the thought of ordering our own kits from PCBW to deep a rabbit hole? Lorne.
20 or 25 years ago I used to sometimes sell things including on eBay that I made but it’s gotten to a point where it’s a complete hassle for small sellers between shipping costs and parts and labour and having to deal with any problems that come up so I find it easier to just provide the information from my own hobby stuff and people can replicate
This is really Great! have you got these working with more than 2 endpoints? I've been looking at something like this for my kids to play with, with their friends.
not yet but I’m planning to work on an expansion switching matrix to allow more notes to interact.
Any estimate on what the BOM for the board costs from something like Mouser?
It's hard to find out because some items I had to get on AliExpress (or maybe ebay has the same options) like the phone SLIC module, and I also got the ESP32, RGB LED and MT8870 DTMF chip on Ali. Also I think the MT8870 may be officially obsolete now so some obscure places may have stock when searched on Octopart but of course Ali has them.
Looking up what Mouser does stock and then glancing at the rest on Aliexpress, I estimate $30USD in parts aside from the bare PCB, but if buying from scratch on Ali it would be higher because for example you'd buy a set of 10 MT8870 chips for maybe $5, so I counted the per unit as maybe 50 cents for the BOM.
If you can remove the trunk line wire and make it Wireless or work on a local or wide area network work over the internet it can make a lot of money cuz I've been looking for something like this without having to install a PBX system
This is really cool. I've wanted to do something like this myself for a very long time. Have you considered the possibility of running some sort of terminal server on one side of the connection, whose behaviour could be influenced by the operation of the Phone SLIMs state. For example, certain dialled numbers could command the terminal server to connect to a telnet-accessible BBS on answer instead of a local one, altering the baud rate of its modem at the same time. It could also simulate randomised busy signals via modem off-hook etc
The project can go in many directions and so far I’m working on various local hardware infrastructure ideas so I’m only looking at connecting physical devices wired together. There’s another project out there that might go more toward network access so over time a bunch of capabilities may exist between multiple projects.
The next thing I’m working on is a multi node server type hub where multiple SLIM boards have their phone cable plugged into a port on it and wirelessly communicate to that to coordinate calls instead of going node to node directly like now.
So if there are four separate SLIM nodes plugged into the hub, when a call is being placed it will be wirelessly communicate to the hub which will determine if the call can be routed or not and then complete the connection path or notify the node of the busy status so it can generate the busy signal on that line.
In that multi node set up one of the nodes could be some sort of terminal interface bridge thing where other nodes can dial that one to do specialized things instead of regular calling to the other nodes.
I’m trying to gradually expand it and keep it modular so things can be changed or reconfigured and expanded as ideas come up.
@@GadgetReboot All understood. It's a great project with many possible applications. I look forward to seeing the hub concept as it comes to fruition. I'll try and make some SLIM nodes for myself - I have a bunch of old ex-Telecom Australia rotary dial phones that could benefit from them!
I have uploaded a video to youtube. For some reason, the option to view the transcript of the video does not exist. It does not appear automatically on the right side of the window and the option to view the transcript does not appear. In other words, when I click on the button with the three dots "...", the option to view the transcript is not there. Please advise. Part of the very reason for me to make this compilation video and upload it was to be able to view the transcript.
Please help or offer advice.
I can not find an option to view the transcription of this video either. Is it a setting of the video maker or a setting with my account?
Hi, nice video. So if I understood, a BBS server should have one phone line for every user connected at the same time? Or it was just not possible to have more than 1 user?
I was playing around with PCs (and even programming games) in the eighties but I didn't have a modem until after Internet was a thing.
That is correct. Most hobby BBS's were a single remote user only (the operator could chat from the console). Also, while these BBS's were in networking mode, exchanging messages with each other, no other users could connect.
Fun fact: the zmodem protocol was created to cut the length of networking calls between BBS's, as a few boards made long-distance connections and thus the 'calling' system was charged long-distance rates per minute. Instead of just batching up raw messages and transferring them uncompressed with xmodem, zmodem would ZIP the files prior to transfer, and unzip them on receipt. Since most of the transferred files were raw text, compression was very effective at cutting transfer times.
@@georgeerhard1949 And how did you accept the cookies? Just kidding. Those were great times, you make me want to experiment with telephony.
Yes, one per caller, I built one using an 8 port digiboard in the early 90’s and had 8 phone lines to it. Eventually you could have a T-1 (ISDN PRI) with 24 lines broken out and a hunt group phone number in front of all of them. Companies made modem banks, rack mounted, that connected V.35 over to the line interface.
These are really magnificent, honestly. Is it possible to connect more than two?
for now it was only designed for two boards but it’s possible that instead of plugging the extra phone line directly from one to another, each board could plug into another sort of switching board where nodes could be routed together as needed
or else if it could be evolved into completely wireless without the need for the extra hard line, data packets could just go wherever needed so it may be something that could happen later if there’s any interest in developing this.
I love the idea of a switching board. It would be amazing to be able to setup a private network with a handful of nodes
That's amazing! How fast could I dial up connection get with this simulator?
probably the maximum normally achievable because I think it’s all just analog tone signalling so as long as the signal integrity on the phone line is noise free, which I would expect on a bench test set up then it should be fine.
I was connecting at 33.6 K and I think the fastest even possible is 56K for standard dial up modems but I can’t remember all of the details.
@@GadgetReboot That's amazing! I might get a couple done so I can give them a try!
oh dang Telegard. I apologize for all of the horrible things I did to Telegard in the early 1990's
Did you get that old phone from Jenny?
it was actually her grandfather's