Reverse Engineering a Cold War Military Telephone
ฝัง
- เผยแพร่เมื่อ 13 มี.ค. 2023
- Join Nick and Rob as we reverse engineer the protocol of a vintage 1980s digital military telephone (the TA-1042) and reimplement a phone switch to convert some door stops into useful phones!
Curious? The Discord: / discord
The TA-1042 is a quite slick looking military phone that uses the CVSD audio codec and a proprietary switching protocol. The project implements a hat for the Raspberry Pi Pico (RP2040) cortex M0+ microcontroller that leveraged the Programmable I/O (PIO subsystem) to encode/decode data from differential Manchester encoding provided by the phone.
The entire project is open source! Future videos are planned with more details on the implementation. If you'd like an assembled version head on over to Tindie:
Source Code: github.com/nickandre/dnvt-fw
Buy a board: www.tindie.com/products/nicka...
Rob's write-up: robruark.com/projects/DNVT/DNV...
This video covers the phones and the process of reverse engineering it. The following upcoming videos are planned:
part 2: hardware information
part 3: embedded programming with the Pico
part 4: USB programming and interfacing these with asterisk
If you want to support our channel and get some fun perks, we are now offering memberships:
/ @nicksknackstech
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FYI if you're interested in purchasing or are curious about the firmware improvements, check out this video on our extras channel: th-cam.com/video/boGw5UdfVxg/w-d-xo.html
Gday . Im been searching high and low for an easy way to make a point to point , over wire.... Keyboard to lcd encoder/decoder. Any ideas ??
@@johansen1010 like you want to connect a USB keyboard to an LCD?
@@nicksknackstech yes but i believe it needs to be the old keyboard that plugs in a pc . The old style ibm keyboard . Then over wire to an lcd . I thought it would be easy but apparantly not
@@johansen1010 PS2 is relatively easy but USB is not so easy. With a RPi Pico you can use a USB “on the go” adapter to connect the micro usb adapter to connect a device. The Pico has to implement the interrupt endpoint querying of a USB HID keyboard and adapt the response to an LCD. USB is unfortunately not simple; I have a video coming up on how to implement a simple USB device but HID has a lot more complexity. You can use a library called tinyUSB but it’s somewhat confusing. Use a search around for some examples to follow on GitHub as a starting point.
Seeing these phones and hearing them ring again after 35+ years, especially that TA-954, brings a smile to this old man's face. Great video!
And this research will progress into being able to bring those TA-954's on the commericial telephone network through eihter a SIM card or a Google Voice account.
Best of all, this old relic can produce music to my ears that is 2,600 Hz BlueBox tone along with having KP/ST/ABCD keys. heh
Woah this man knows SQL as well as military tech. A true dual threat.
Damn I guess he could be considered a foreign threat, iguess he's going to get deleted by the "tiktok ban" bill, oh well
"dual"
In 1994 maybe....
Awesome work and great video making!
Now this is a compliment
Well if you say so consider me subscribed.
Well if you say so consider me subscribed.
I have this wierd feeling that I'm seeing the birth of what will be a pretty big channel. Excellent work.
"Ha. You thought I'd have a long annoying intro that you'd have to skip."
That deserves a like. ;)
I aspire to provide the entertaining aspects of TH-cam and remove all the nonsense that makes me irate when I watch videos 😂
@@nicksknackstech That's a good direction - we all want it. And yeah the above line resulted in a sub :D
I love seeing young people this down and dirty with the hardware, especially with old odd ball stuff. It's neat to see the old fused with the new too! Looking forward to future videos.
hear hear!!
It's amazing what we can do nowadays using modern technology. Every piece of hardware and software eventually becomes obsolete as computational processing power increases especially in breaking codes.
I thought your channel would have a bunch of videos, given how good you are at making them! Awesome job! Subbed!
I’m working on it :)
Following the protocol for a channel explosion.
Me, too. Subbed and joined. More C and hardware interfacing, please!
@@milk-it oh if you want C just wait till the firmware video :)
@@nicksknackstech Can't wait!
First youtube suggestion that i actually enjoyed! Surprisingly loved the presentation and format.
Thanks! I've watched enough TH-cam to learn everything that annoys me in TH-cam videos and avoid doing it :)
The unintentional (intentional?) comedy of the continuity error of the change in crayon color during the differential Manchester encoding explanation section had me laughing so much that I couldn't pay attention!
that got me too hahah
I was wondering who would be the first to notice that 😂 I tried to film the B roll with the original color but the contrast was a bit low for the video.
@@nicksknackstech At first I just thought the white balance of the camera might have been off on the closeup shots.
@@Andy-lf4di ya boy doesn’t use auto white balance 😂
And here I was thinking I was nerdy for adding a TA-977 to my TA-312 handset. Great job fellas.
We’re investigating making a similar box to switch with analog field phones with dial capability. Surprisingly it’s a bit more complex but stay tuned! Also once we get this working with asterisk it will work with the standard analog telephone adapter stuff.
By the way does the TA-955 signaling adapter need a 6 volt battery or is it happy with 9V? Online I see the Duracell J battery available with 6V and some Chinese lithiums at 9V
@@nicksknackstech My commo room didn't have 955's, we had a TA-977 as an accessory to the SB-22 Switchboard. The 977 used a 9V.
@@roberttackett7000 what was the idea there? Was the switch board treated as a PBX with the DTMF signaling used on a trunk line back to some sort of automated exchange?
@@nicksknackstech I replaced the battery in my 955 with two cr2032 battery holders in series, works great
Great video, glad TH-cam recommendations are working again for smaller channels! Subscribed! :)
Thanks so much!
@@nicksknackstech Exactly - someone's finally fixed the algorithm xD
@@aktuelPL either that or TH-cam has been broken with nonsense sponsorship churn 😂 The idea with this channel is to create the kind of content that I would like.
Hi Nick! I know nothing about you or your background, but as a former Infantry platoon sergeant, you remind me of one of those PFCs or Specialists you run into in the S6 (Communications) shop on very rare occasions who really, really knows what the hell they are doing. I treasured those folks then, and I treasure them now. The tipping point for me was your crayon on paper explanation reasoning. I agree, if you can't explain it with a crayon and a sheet of paper, you don't know what you're talking about. Subscribed, my friend.
Thank you kindly; I do my best to understand what I talk about and keep quiet when I don’t 😂
I also find that the first time I really learn material is when I have to teach it. In the making of this video and some of the upcoming ones I have to think a lot through the whole process and double check my own understanding. It’s funny when I realize I missed something only when previewing the video.
Those extra button are precedence codes. Normal (no button), Priority, Immediate, Flash, and Flash Override. This had to do with the military telecommunications architecture and system - essentially, different levels of precedence were afforded to different levels of command. This had to do with the fact that in case of an all out war - or god forbid a nuclear exchange - some traffic was more important that others, so by using precedence, you could pre-empt the use of trunks, or kick other users off. Flash Override wasn't technically a precedence but an ability - and it was limited to the National Command Authority, nominally POTUS or Theater Commanders.
Yeah the phone doesn’t seem to do anything special with the characters other than transmit them to the switching equipment so our device just passes them through. My understanding is that if a call was in progress and a higher precedence call was received, the switch would emit a tone and swap the call. Then there was some amount of configuration (authorized precedence and data configuration) made on a per line basis on the switch side.
I can confirm the precedence codes. Do you know what the R and C buttons do? Military keypads I've seen had the star and pound keys in those positions, but with a five-pointed star instead of an asterisk.
@@jeepien R is Routine, C is Conference
@@jeepien one manual I saw stated that R key is for operator; it instructed people to use it to set up a conference if their line wasn’t enabled with conference permissions.
If you ever end up with a surplus, my recommendation is to send a pair of phones and a PCB kitset to LMNC's This Museum Is Not Obsolete so that the geeks of the world can get a real hands-on try of your wonderful project :)
I'm 3 min in and I already know this video will have millions of views in the near future.
It has all the hallmarks of a bomb as video, I've seen it happen a billion times.
Who else wants to see the dog making coffee?
Thanks a lot for a very entertaining video!
You have me wondering if I could train him to press a button in the morning connected to the coffee machine.
You've got my sub mate for this movie! This kind of sense of humor is what we want to have on TH-cam ;) keep posting videos like that ;)
The industrial design on these is so sweet
Yeah they really hit the nail on the head with the TA-1042. That’s why we were interested in taking a look at these. Some of the other phones, not so much though 😂
I have a feeling that much of the aesthetic appeal of military commo gear is accidental but so be it - I love anything this overbuilt and, in the case of military HF gear, superlative performance.
Fantastic work. Also, the link in Rob's writeup to the military report was a hilarious read. They sure weren't all that happy about the switch unit, hot, noisy, broke down all the time, unlogical, the contractors that built it were practically running the things for them. And you stuffed it in a lunchbox. Nice. Subscribed and looking forward to the hardware vid.
Thanks! To be fair we do owe some of the improvement to better modern electronics (not that we aren’t ninjas). That and the whole MIL-SPEC nonsense.
@@nicksknackstech
One can't expect you to park a massive truck full of obsolete and dubious tech in the backyard to make a nice YT vid right?
Maybe if you hit gold playbutton you could do a special where you actually get one, get it to work and compare it with your solution?
Would love to see that.
@@dokterzorro if I could find one I’d go on an adventure :) I showed this off at the Mike and Key swap meet near Seattle a few weeks ago and one of the guys mentioned seeing one of the trailers at a surplus auction many years ago. I believe these have been decommissioned a while ago so I’m uncertain where I would find one. They may also have had key bits removed that involved any sort of military encryption.
High quality content, thank you! Glad I stumbled upon this.
I can't believe ur channel only got 2k subs! That's crazy! Amazing work guys! Can't wait for ep 2
This channel is giving Rick Moranis taking up electrical engineering as a hobby in his time away from the silver screen.
Hey, nice video - cool phones, fun project, well explained! Looks like I'll be sticking around :)
Nice to see it made with old video gear.
Gotta watch the hardware teardown; just a glimpse and oh my... Thing of beauty, joy for ever.
I really appreciate you making these videos. This is the first time I have been on your channel. I usually watch Hash on Reverse Engineering News. I'm going to have to watch this vid a second and maybe a third time before it all sinks in but I think this is a project I want to undertake. I'm going to see if I cannot buy a couple of those phones on eBay. Cheers!!!
Wow. This is a lot more interesting than I originally expected. Well done.
13:06 I LOVE your definition of the concept of "bit banging"...so well done! Great personality in these videos...very inspiring!
Thanks so much! I find the hardest part of mastery of a subject to be teaching and explaining complex subjects in a comprehensible fashion. It’s quite an art :)
@@nicksknackstech Indeed, but an art that you are doing very well! I hope to see more like this! I've restored some rare vintage terminals that use "modified Manchester encoding", which I displayed at VCFMW last year, and will again this year. So, your topic has high relevance for me. You're doing a GREAT job explaining and entertaining simultaneously. Please, keep it up!!!
This was an awesome video. Super informative and humorous. You got my Sub.
Excellent video! Well explained and very entertaining.
i watched the first 4 min of this video and u already won my subscription, ur awsome keep it coming
been stoked for this vid since you posted your short on these phones haha
I was an Army platoon leader in the late 80's and early 90's and we used these phones all the time. It amazes me that an entire truck-mounted switch and generator set can now be replaced with a device that fits in the palm of your hand.
Rob pulled some witchcraft with this one. Quite impressive. I kind of want to gang a bunch together in a rack enclosure.
To be honest, your "old times" material has thousand times more privacy than our so called "smart"phones. I constantly keep telling mine to stay on privacy mode and he still shares stuff with those GAFAM...😁
@@danjim249 yeah all the phones have a totally separate computer inside the modem that’s not controlled by you, lol. I believe it can still ping the tower if the phone is completely off unless the battery is removed.
@@nicksknackstech
It means certain compromises, but I don't buy phones with integrated batteries for the reason you mentioned, AND so that I can run a pair of batteries with one in use and one on charge, resulting in a handset that is never out of service "on charge". I can also go "out" with a spare battery and operate off grid for longer.
My current outrageous brick: Hytera PDC760 (hybrid android phone / UHF DMR radio)
My next unit will be: Motorola ION (hybrid android phone / UHF DMR radio)
Alternative slim version Motorola LEX11 (Android only - removable battery)
Watched 2.5 minutes -> subscribed. Good Work!
So cool and interesting. Very well done! Thank you very much.
This brings back memories, learned all about these in AIT, we had boxes of them and reels of cable (WF-16) to wire them up. Worked on a 39D and then transitioned to the SSS (AN/TTC-56 if I remember correctly). The software ran on an ancient version of Solaris
Awesome video guys, keep it up! I'll be creepin' and peepin' all of 'em 😃
This is so cool! Well done man!
Wow what an awesome video. Thank you!
This is super cool! I love that someone is out there dissecting this old miltech stuff to make it work again...and in a small form-factor, too (who's got huge comms trailers of stuff to hook up to, right!?)!
I do kind of want to stuff these into a rack enclosure 😂
I have to do it with my intercom. Thanks for the idea!
Super interesting! Subbed, can't wait for more videos
Man I remember when we got these as replacements for our TA-312s. Huge upgrade.
Awesome channel. Cant wait for more videos
12 am and I'm watching Rick Moranis mess with some old phones. Absolutely sensational
Lol hey Rob! Was not expecting to see you here. Awesome video!
Thank you so much for using a nearly silent writing tool!
Not a fan of screeching sharpies?
@@nicksknackstech exactly!
Interesting, nice work as well!
Awesome work!
It would be interesting to make the switch support an ethernet connection and sip. Then it could be tied into an Asterisk system with full PBX features. It could then also fulfill Artem Andreenko's wish of being able to use them over Starlink dishes, ham radio, or the internet. If only I had a couple of those phones....to eBay!
If you have ideas feel free to reach out (email is on the channel with TH-cam in the browser or there’s a contact form on the website). We are working on asterisk integration; the main snafu is that the native data is CVSD. Easiest way would be to get asterisk to integrate a CVSD codec upstream but for personal use we can add a patch to include the CODEC. I don’t really want to transcode before asterisk because these can be used for data calls as well. I was looking at both SIP (using PJSIP) and DAHDI for integrating the switch and not sure which is better/easier. SIP may be more flexible but I’m not sure how to structure it (ie say we have a console app with 8 extensions, do we run 8 SIP instances?). We are also working on a POTS version to which we want to add some sort of radio interface to allow the system to integrate with a repeater controller or HT. As for just being able to use these over starlink I was working last night on prototyping a simple websocket server to allow multiple console apps to call each other. I think I’ll have that working in a few days. If you’re interested in helping development I stocked up on these phones before the video release so I could probably spare one if you need. Sorry for the ramble lol.
@@nicksknackstech Not sure if things like chan_mobile or the bluetooth chan module to attach a phone to asterisk will help you a little
@@SuperSpecies I think I may try SIP first since many people may want to use this as a stand-alone IP phone. The closest example I could find was this PJSIP demo file for integrating third party media. It would also require registering a CVSD codec with asterisk which we can do. github.com/pjsip/pjproject/blob/master/pjsip-apps/src/3rdparty_media_sample/alt_pjsua_aud.c
After that I think looking into DAHDI would be the best bet assuming I could use it with a non-PCM audio format.
Great job, amazing
Instantly subscribed before even getting deep into the video because of the trolling-type humor.
If I can promise one thing it's deadpan humor and dad jokes :)
Love these reverse engineering projects! its like a puzzle
Yeah this was quite a fun combination of EE, mathematics, and embedded programming. I was thrilled to discover my neighbor down the street wanted to do a project with these phones and then fortuitously happened upon the RPi Pico’s PIO feature. There was some element of fate here, but I’m pleased we were able to complete the project and deliver a functional and manufacturable device that’s entirely open source to interact with these phones.
Great video :D
The red buttons are for the MLPP functions. There’s a lot of information online, and their voip equivalent: as-sip
Good times! Used to use these hanging off an AN/TTC-42 or an SB/3865. Good old Tri-Tac.
"Near midnight, when asked to surrender, he replied with one word; 'NUTS!'"
We used these phones inside our TOC field tents in the late 90's/early 00's. There'd be wires EVERYWHERE, and the hub looked like a nightmare. I was a networker and dealt with messy patch panels all the time, but those DNST panels? Yeah, no thank you.
Nice choice on the use of GDT's (gas discharge tubes) on the telephony lines. This looks similar to designs I made back in the 1980's.
Rob doesn’t design electronics half way ;) They ain’t particularly cheap either, around $4-8 BOM cost per board for 8 of them.
I remember when these came out. Wow!
damn im impressed by that u only have 746 subscribers...just keep the quality like this and people will come in masses
Thanks man! Well I’m just getting started, we had 60 before this video so it’s doing alright :) I’ve had a lot of video ideas for a while but it’s a lot of work, so I’m working on getting a rhythm. I also tend to spend months tweaking a single video like this, so I’m working on optimizing my perfectionism.
The Army Switching Net Equipment (LEN or SEN) units typically came mounted on the back of a humvee (like a truck camper). Spent months at Ft Gordon (err...Eisenhower) on these....never to actually use them. So much for the glorious Mobile Subscriber Equipment (MSE).
I would love to find one :)
Blown away, great video! Can't say for sure it was the same model, but we were still using a phone that looked like that in 2006 in Iraq. Every week or two, I'd spend several hours walking the wire to find the the brake and repair it.
Many of my phones have date codes from the mid 90s. I believe they were used up until the mid 2000s. My military fax machine manufactured in 2008 still included the DNVT data cable.
No tdr equipment for finding the distance to the fault?
@@glennmcgurrin8397 hmmm what’s the frequency required for TDR? These are relatively low frequency but it may be possible to implement such a feature.
@@nicksknackstech More of an impulse response kinda deal. Send a sharp pulse down the line and look for ringing coming back. The time to the ring is how far away the fault is. Speed of light in wire / resolution would give you an indication on what ADC sample rate you'd be looking for, but I'm pretty sure the answer is going to be "lots"
With no fourth row button pressed first, the call is Routine Precedence; the buttons are in increasing level of precedence: Priority, Immediate, Flash and Flash Override. They served to establish the importance of the call to the switching system, which could dump calls ov lower precedence during congested utilization.
I did hear about Manchester code from a old guy at the ham radio club some 30 years back. Did take notes down. But missed most of it. Thanks will have to look for some of them phones and have a play.
Great video. Keep it up 🎉
Nick - you look a lot like a young Rick Moranis. You need to put "LUDICROUS SPEED - GO!" into one of your videos.
Nice job!
this is very cool! excellent work to both of you! *(And HI MARC!)
The button on the handset that makes tones on press and release is a PTT switch for RWI (Radio Wire Integration) applications.
We want to build another box for POTS phones and our plan is to include a radio connector that will key walkie talkies based on that tone.
Very interesting that these phones use the same encoding method as floppy disks. I didn't recognize the term differential manchester encoding until you started describing how it works. And I suddenly realized I already knew this. It's just that I call it by a different name "FM encoding." I suspect then that, like a floppy disk, the data being transmitted is actually analog but transmitting using hi/low signals. And then the phones basically function as modulation/demodulation devices like modems. I'd imagine that in a military deployment, the connections are way under par, so you'd want a protocol that is robust and can transmit even in the worst of transmission conditions. And FM encoding would be a great choice.
The encoding is digital and it uses a rather clever codec that was very easy to implement in 1980s ASIC tech - we managed to implement a codec in python and we will do a video on it soon. It uses a leaky integrator, a shift register, a variable gain amplifier, and a comparator. A “1” means increase voltage, a “0” means decrease voltage, and then if you get 3 1s or 0s in a row it will increase its gain per step. Both the gain and the absolute value of the output have a decay time constant. There’s some military spec docs on the required behavior of the system in response to defined inputs.
Man that whole form factor would make for a sweet HAM radio, you already have a PTT button and DTMF or tuning buttons, all you need is a little display for the frequency. Could be a great project for someone to attempt!
Yeah we are looking into some sort of radio interface for these. Also some idea for an open source digital radio system.
This video is definitely underrated.
My mom rates it very highly 😉
This is really cool!!!!
wow excellent video!
Glad you liked it!
Tangent time = Subscribed
Great video
🐶
I used to build MSRT for MSE for Thomson CSF. There was an extra slot in the radio for a card called the spy. It showed all the call setup and teardown. The commands you use are just like the radio had but it also did a RSS receive strength and assigned N0 thru N3 number and sent that to the far end to adjust transmit power. It also performed a bit error rate test with all 1s all 0s and quasi patterns during call setup.
8 radios plus a GLU formed a cell site. The phone used 16khz bit stream but was upped to 19.2 at the antenna for overhead and crypto. They even had a fax machine option.
Funny enough we did scrounge up a DNVT compatible fax machine. Still trying to deduce exactly how to use it.
idk how, but glad I found you. the beanbag chair is mine
You absolute mad man, of course I see this after I've gutted one of mine to go the CuriousMarc route
You can buy replacement keypads if you saved the original guts. They do come up for sale from time to time. The only weird part about these is that it disables the keypad during the “traffic” mode with the exception of the R 0 and C keys at the bottom. But we are able to seamlessly/temporarily transition the phone back to dial mode, pass receive audio to the handset, and the user can dial. Then another key can be mapped to restore the phone to traffic.
This is dope.
Wait a minute. This is the second video on this cannel? Below 4k subs and it still reached me? TH-cam works man! :D Great, Great stuff you did here. High effort indeed.
Yeah I’ve been somewhat impressed at the interest this has been generating. We had 60 subs before this video.
Tangent time theme song on point!
8:39
you had me at "Today's knack is"
Nick’s got knacks
Great stuff :)
Love your video! From 2000 to 2004 I was in 440th Signal Battalion. The switch board that DNVT's connected to was called a SB-3614. The technical manual for the TA-954's is TM 11-5805-735-12. I have sent emails to some old timers to see if they can dig up a digital copy. I have a couple DNVT's and I'd love for them to be actually useful. First connect the DNVT to the switchboard with WF-16, Second you would then pickup the handmic (H-250) and dial phone number then push R to register that phone number for that phone to the sb-3614.
I was confused for a second with differential manchester then I realized, "Oh, you mean conditioned diphase!". I was a maintainer for the TTC-39(A)v4 telephone switch (and a few others), the "10-42" were standard phones with the KY-68 being the DSVT. From the Autovon days, those extra buttons were for priority calls . FO being "Flash Overide" or the highest and P being "Priority". Flash Overide was special since it wasn't a precedence but a way for the President or other high ranked person to preempt any call on the network. If there were no open trunks and someone was calling back routine, they'd get yeeted right the heck off for the bosses call.
Man, what a powerful example application for those PIO pins.
They’re wild. Such a flexible setup with no equivalent in industry right now. We are looking into a POTS version and I can basically construct any arbitrary TDM format using a PIO system; Heaven forbid I try to do that on another microcontroller, probably 10x the cost and a data sheet just as long.
@@nicksknackstech I feel like the biggest challenge to using the RP2040 in industry is that everyone trained on AVR / PIC views it as a hobbyist toy because it’s associated with the Raspberry Pi.
I think it will go the way of the Atmega 328. We all used it in college, and now as design professionals it’s the familiar, cheap chip we reach for when we’re doing low volume, quick turn work. Even if (in the case of the Atmega) it’s not necessarily a great chip anymore. That’s how this thing is going to get into real product use.
The thing is also like one literal dollar on Digikey right now. That can’t be said for any other microcontroller you’d actually want to use!
@@michaelmolter8828 and you can actually buy them, lol
11:08 Tangent Time!...good synchronicity @ 11:11!
Very cool! Reminds me of my 4-line very-much-not-military-grade analog relay switch project from a while ago. I am curious though - if these military telephones are not designed to be secure, why do they need to be digital, and not just a ruggedized POTS-type phone? Signal integrity or perhaps overall system complexity? Incredible presentation nonetheless, and I am surprised at how few subscribers you have. The use of real analog video (not a plugin!) will always make me smile ;-)
Well prepare yourself for the Saticon tube video 😂
I’m actually not sure why they opted for a digital phone in this case. There was a secured version (DSVT) which are not readily available in the wild as well as a secured handset called the STU-III which used the LPC codec to achieve lower bitrate. I would guess that part of the motivation here was a common network infrastructure for voice/data/fax as the output connector at the bottom exposes a data interface. We have acquired a fax machine that can use the data network feature and will do some more playing with that in a subsequent video.
nice work :D
We called it 'conditioned di-phase' in the military. The great thing about it is that it has the timing for the signal built in. You should be able to capture that timing with the arduino.
I’ll cover the timing during the firmware video, but the main issue is that the phones do not synchronize to the output clock. They are guaranteed to synchronize the rate but not the precise timing. So each PIO that’s doing the receiving may have different timing. The advantage of the PIO is that the clock can be set to 16x the data rate then each state machine can be offset in units of 1/16 of a period. Doing it with individual state machines also greatly simplifies the software side.
Funny running across this video, I was thinking about this just the other day, that phone I mean. I preferred the crank phones. They electrocuted you, but they worked.
The crank phones are up next :) though probably with the dial adapter, so not using the crank. As much as I love it 😂
Interesting way of presenting.
I still cannot figure out whether this was intended as a compliment 😂
19:00 nice explanation of a handshake
edit: reminds me of back in the 80s / 90s we used to have modems with mnp compression and the like, v92 so on.. anyway we had to have a handshake, as we all know the good old modem connection sound (AOL made it famous I think) but you've gotten way deeper into it with these phones. Pretty fun!!
Heh the modems are substantially more complex I believe - the handshake here is a single byte followed by a byte response without any sort of training or line characterization. I believe modems and later DSL equipment have all sorts of ability to negotiate different schemes of transmission depending upon the quality of the link.
In an upcoming video we have one of the fax machines that connects to these which I’m still wrestling with a bit, which I believe has similar sorts of handshake protocols (which is quite a headache when you combine proprietary military functionality). It does have standard ITU Group 3 fax facility and I was hoping to find some sort of open source fax system or T.38 implementation but I’ve been struggling a bit.
@@nicksknackstech I'll look around, ask around a little. I know a few people who were in their prime in the 80s and are all old IEEE grads.. as a matter of a fact one gentleman i think is still with us worked on military hardware back in the day.. if i come up with anything less than obvious I'll get it to you. Thanks for the reply!
Love it! I am going to have to pick this up because these phones are something I have been wanting to tool around with for some time. Thank you for this! Can it expand to a larger switchboard? Say 12 phones with three switches?
The current demo host program can take multiple switches and make them act as a single unit over USB. It’s not really in a great state. But we have some folks on the discord looking to rack mount them. If you’re interested in acquiring some of the bare boards without the case it lowers the BOM cost quite a bit, just let me know.
Just so cool!!!!❤❤❤
"one kiloherth" is my new favoriate term
The phones we were selling to Wall Street at New York Telephone in the 1980's and 90's were total crap compared to these phones. Especially after 911, Hurricane Sandy and then the pandemic, business started thinking about disaster recovery more. The military constantly prepares for surviving disaster as demonstrated in these devices.
Yeah they're rather indestructible (save some of the plastic chipping off). All the boards are conformal coated and my friend said that their maintenance for these consisted of rinsing the dust off the boards with water :)
This way above my pay grade !
I saw those telephones ,but we never used them .
We used the ta 312 and ta1 and the sb22 switchboard , and the 12series radios .
I was in the national guard , so that’s not saying much , l know . There were newer systems being deployed around 1990 .
And on the civilian side of things , these cell phones . So this vid blows my mind .
We are looking to implement a switch for the TA-312 with the keypad adapter. Those have always held a bit of a sweet spot in my heart, such a fun device.
Dunno why I’m coming back to this video. Something magical about reviving something that that has no hope of ever working fully.
Yeah it’s fun to do projects on these sorts of devices that no sane or pragmatic business person would ever investigate. Plus it was a lot of fun :)
Definitely hoping to see another similar project from you soon. And don't doubt yourself. This is gonna be a huge channel soon.
interesting. I was stationed in Germany with the US Army from Jan '89 - '92 at a front line Combat Engineer unit. The Berlin wall fell in the fall of '89. I never saw one of those phones. Only the Vietnam era phones, we used those in the field (practice combat operations in the German woods) and calling from building to building inside the kaserne.
Were you using DTMF adapters or with switchboard operation? I’m not entirely sure when these rolled out; most of the TA-1042s were made in the early to mid 90s that I have judging by the date codes. The paper lists the development as taking place in the early 80s.
i'll never forget working with an ardiuno for a class, the project was make a remotely accessable IR alarm that would send an email or something right? Midway through the project the company that made the web service or whatever you call it that we were using simply discontinued said service. Our teacher, understanding, did not screw us over. But if I'm ever walking down the street and I see that companies mailbox? It may not go unshitted.
When in doubt, write it yourself in python and run it in AWS lambda.
@@nicksknackstech wish you’d been round back then. I could model just about anything in solid works, but that? No clue