Russian phone dialler using interesting magnetic memory tech
Ғылым және технология
Russian "Trill-2" phone dialler using the same magnetic memory tech as used on the Apollo flight computer.
Schematic here : electricstuff.co.uk/trill2.pdf
mikeselectricstuff merchandise : mikeselectricstuff.creator-sp...
Пікірлер: 539
Before anyone else comments, yes it will be heading to Sam ( Look Mum No Computer)
@unmanaged
2 жыл бұрын
was just about to comment... :P
@LOOKMUMNOCOMPUTER
2 жыл бұрын
hey up it is very intriguing indeed thanks a lot mike!!, for anyone interested it will be available to be seen at this museum is (not) obsolete. :). and ill be dropping something else off for mike to pull to pieces!!!
@tekvax01
2 жыл бұрын
@@LOOKMUMNOCOMPUTER Proper job Sam! Cheers!
Russian word for "firmware" and process of updating/flashing a firmware to this day is "прошивка" - "sewing in", exactly for this memory type. And Soviet philips-like screws were notoriously shittty because lack of real standartisation, wrong alloys, bad manufacturing a were basically only used once. You may even call them anti-tampering screws. Proper machinery and electronics only used flat-drive screws.
К155 chips are TTL, equivalent to 74 series (not 74S or 74LS yet). 74LS would be К555, and 74S would be К533. ЛА1, ЛА3, ЛА7, ЛА8 are different configurations of NAND gate with open collector output. ТМ2 is a dual D-flipflop, equivalent of 74x74.
I wasn't guessing rope memory, that's hilarious and kinda great!
Oh hell this needs to end up in the ‘This museum is not Obsolete’ along with the rest of telephone stuffs, even if it’s just a loan.
@zaprodk
2 жыл бұрын
YES!
How about donating it to Look Mum No Computer on KZread? He has a small museum and might be interested in displaying it.
During childhood and school years seen these in my parent workplaces and in other Soviet offices. Knew that these devices are related to dialing, but didn't knew in detail. Thanks about explaining.
The logic chips are 7474, 7400, 7401, 7422 (none of that 74LSxx rubbish). The transistors are indeed germanium, and quite obsolete for '85 (МП25). In fact the entire design appears to be based on what was available back in ~1975 in Soviet Union.
@marcus0018
2 жыл бұрын
just what I was thinling
Неожиданно) спасибо за обзор, я прям вспомнил детство, МП39-МП42, к155ла3, схемы в инструкции, все такое родное)
@TheKelikat
2 жыл бұрын
в том и странность что германий вместо кт315, хотя в перемешку со 155
These weird mega-jumbo magnetic rings were standard issue in Russian military equipment. That is how they stored parameters in the tube-based missile controller I was fiddling with while in Finnish Army in 1970s.
@TheKelikat
2 жыл бұрын
в приборе много деталей из 70
@karaffens
2 жыл бұрын
Probably also quite relieable in harsh conditions 🤔
This is how ANI-B used to work in the US; which was used when your local phone switch needed to obtain your phone number and send it forward (as tones) to a centralized billing system (e.g. CAMA). They ran your physical phone line through a series of rungs corresponding to the last 4 or 5 digits of your telephone number; and when your switch connected to the accounting system trunk, a polarity reversal triggered your local switch's register/sender to bring in the ANI-B system, apply a high frequency tone to your line, and detect which digits (in which positions) to register in the marker [IIRC].
This looks like something "Look mum no computer" may enjoy.
@LOOKMUMNOCOMPUTER
2 жыл бұрын
you are not wrong haha
@tekvax01
2 жыл бұрын
@@LOOKMUMNOCOMPUTER Sam!! you should contact Mike for more information! :)
@JamesUKE92
2 жыл бұрын
Came to the comments to make sure LMNC had spotted it! Right up his street!
I dismantled lots of Soviet equipment in early 90s. I'd say this design is somewhat 70s not 80s because of transistor choice. In 80s they would've used KT315/KT361: silicon BJTs and way more compact.
Have an even older Japanese version that can handle 20 stored numbers of up to 12 digits, using figure 8 shaped ferrite cores, and all discrete transistor logic inside. It works by running a single sense wire through all the cores in a row, and then generating a current pulse through the digit wire, and having a counter generating the dial pulses, running through the pulses till the sense wire for a digit stops the count. End of number is another core, that does an inhibit of dialling before the first pulse is created, unless you are using all 12 numbers, which automatically does the inhibit on the end of the last digit. Was used for many years in a pharmacy to call suppliers, storing all the common numbers for them, so the pharmacist did not have to look up the numbers, instead having memorised which button was the desired one. Press the button and press start, and wait for the speaker to have the ringing tone, or a busy tone, and then, if busy, you pressed reset, which dropped the line, or picked up the phone, which also reset the device, but also connected you to the line as if the device was not present. Old, dates from the 1970's, and all very crusty inside as well, but a fascinating bit of by now very crusty yellowed beige plastic and old SRBP board, with dozens of small separate soldered in daughter boards, some potted, some not, and not an IC anywhere in sight in it. All boards are tinned copper traces.
Спасибо автору за рассказ, как-то раньше не попадались такие девайсы. Посмотрел, оказывается были и Трель-1, и Трель-3.
@djonidon
2 жыл бұрын
Я только видел рекламу в журнале Радио.
Handy for those times where you have to call 40 people at the Politburo to get authorisation to requisition a new potato peeler.
@silverXnoise
2 жыл бұрын
The shift bank is the peoples’ bank. ✊
@sillysad3198
2 жыл бұрын
lol! it is particularly funny if you know the subsequent fate of this potato peeler.
Love this! Reminds me of the "Tormat" memory used in Seeburg Jukeboxes to remember the song selections. Tormat = toroid matrix.
I never expected a dialer to use DIY rope memory programming but now that I've seen this it's actually a really clever implementation, for sure cheaper and way more reliable than the cheapest option for adding digital programmable memory back when it was made. Many thanks for making the video! The weirder the technology and product you take apart, the better the videos! As a fellow light art installation/hacker I obviously love all your LED related posts - especially since you're doing such large scale installations, but one of my favourite videos is the RAF Sepecat Jaguar gyro. The level of engineering in those gyros are some next level stuff... Also - love your tea cup! :D
You're right about those chips being 7400 equivalent. There's a fantastic Wikipedia article for the Soviet IC designations: en.wikipedia.org/wiki/Soviet_integrated_circuit_designation - the last digit usually refers to variants of the same logic type. On there I can see К155ЛА3 and К155ЛА8 (2-input NAND gates with two different pinouts), К155ЛА1 and К155ЛА7 (4-input NAND and a later production version), and the К155ТМ2 is a D-type flip-flop. Be careful when you search for these because "К" is not the same as the Roman character "K", and "ТМ" is not the same as the the Roman characters "TM", even though they look very similar! (and quite literally identical on KZread's font)
Brilliant solution given the tech constraints they had. I'm impressed.
I really someone involved in the original design sees this and leaves a comment. The Soviets always seem to have found a way to solve a problem, often with limited resources and generally very reliable solution as well.
@yoksel99
2 жыл бұрын
The original design appears to be going back to 1970s, according to the choice of components.
When you could trust your users weren't dummies!
Came from Look Mum No Computer. Both are very fascinating vids! Thanks for getting into more of the metal. I loved hearing about it and seeing this clever tech~
Это не "магнитная память". Это "магнитный дешифратор", позволяющий простой протяжкой провода сквозь кольца задавать набираемые цифры. В последующих реализациях данный узел заменялся в начале рядом "джамперов", а потом вообще всё перенесли в "микроконтроллер"(580ВМ80)
@Doppelhorn
2 жыл бұрын
While this is not an example of "core memory", where information is stored in the magnetization of the cores that can be changed (RAM), this device does make use of a "rope memory" much like the ROM that was used in early computer applications for permanently storing (or "encoding", if you prefer) programs and data. Хотя это не пример «основной памяти», где информация хранится в намагничивании сердечников, которые могут быть изменены (ОЗУ), в этих устройствах действительно используется «веревочная память», как и в ПЗУ, которое использовалось в ранние годы. компьютерные приложения для постоянного хранения (или «кодирования») программ и данных.
@Ma_X64
2 жыл бұрын
ВМ80 -- значился как процессор, а не контроллер, и требовал немало обвязки.
@chveyk
2 жыл бұрын
@@Ma_X64 "немало" - для реализации "компьютера". Для работы в роли "контроллера" - не так уж и много. Могу напомнить, что большинство первых АОНов было собрано либо на ВМ80, либо на его "аналоге" Z80. В общей сложности АОН содержал "аж" восемь корпусов микросхем ;) И имел приличный функционал как для самого АОНа, так и в роли "звонильщика"(если память не врёт - до 128 номеров в "записной книжке" с произвольной выборкой и любым временем дозвона). Чуть попозжа, когда в "наш" мир пришёл прогресс - многие открыли для себя контроллер С51(8051) - кол-во корпусов микросхем в АОНах разительно сократилось.
@Ma_X64
2 жыл бұрын
@@chveyk если что, контроллер это по определению процессор+периферия в одном корпусе. И дело тут вообще не в вычислительной мощности.
@Integral2128
2 жыл бұрын
@@chveyk ВМ80 никак не аналог Z80, ВМ80 аналог говнопроца от интела i80, Z80 имел и частоту больше, и доп инструкции, и работал чуть по другому для более удобного программирования
It’s videos like this that make me wish KZread had something stronger than thumbs up. This is awesome!
u could hook a bunch of xmas lights to it and use the number storage to create different patterns
Such a unique design, you would not expect core memory in this kind of device. The engineer did a great job bringing his idea to life.
This would be a perfect fit for "This Museum Is (Not) Obsolete" museum!
@joe214
2 жыл бұрын
I was just about to comment the same myself!
I finally understand how the magnetic core memory worked .. I used to think a lot more magic goes in this
@Olegach21
2 жыл бұрын
This is the ROM, the RAM is where the true magic begins to unfold :)
For the first time I actually understand how these cores work. Rather ingenious, actually.
The PCB material is actually the usual fiberglass soaked in epoxy. What gives it papery feel is the glue that was used to attach the foil that was etched out. And of course having no solder mask is an absolute soviet tradition.
@pashko90
2 жыл бұрын
Still to current days.
@thelittlebigoneru
2 жыл бұрын
@@pashko90 still to current days what? :) FR4 as PCB substrate of lack of soldering mask?
@pashko90
2 жыл бұрын
@@thelittlebigoneru Some army pcbs i seen without a soldering mask.
@thelittlebigoneru
2 жыл бұрын
@@pashko90 probably, it was transparent mask, it is used to enable visual check of condition of copper layer. Copper, exposed to ambient air, is strictly prohibited by regulations and can't pass military QA, not in soviet era, not today.
when you said core rope memory i imagined some kind of way for you to program the numbers in electrically, i was not expecting instructions on literally wiring the number in by hand in this way, very interesting
@djmips
2 жыл бұрын
On the Apollo computer you will see videos of workers sewing the ROM, which is mind boggling. Every release required the rope memory to be updated.
Look Mum No Computer would love to have this. He actually has the equipment to use it.
@Shiba643
2 жыл бұрын
Rope memory relay sequencer?
This is one fantastic Forgotten Machine! Thanks so much for preserving it and showing it to us!!!!
Really interesting, love soviet electronics, I used to repair those little Regonda M, TV sets in the 80s, those top hat transistors are awesome.
When I was a kid I found something similar at a charity shop but it was an electro-mechanical version. It had a plastic film that was driven by a small motor over sprockets. On one side was a sliding pickup with two contacts that rode on the film. You slid it up and down to select the number to dial, then pressed a button to start the film drive. On the film were places to fill in squares with a conductive pencil to "program" the numbers to dial. To dial a three you filled in three squares, etc. As the conductive squares passed over the contacts, it shorted them performing pulse dialing.
@stevebollinger3463
2 жыл бұрын
My grandfather had one of those. In the late 1970s. It basically was like filling in a scantron test. And as you say instead of writing a 1 or a 3, you filled in consecutive squares. You could hear it go click click click as it dialed. It ran the pulses out at 10/s just like a dial. Essentially that system didn't store the numbers at all. It didn't even have any idea what it was dialing. It even looked like this unit in general shape, with the belt on the left where the cores are here. And you have to life the cover to program it like on this, but of course you did it differently. You wrote in the name of the person associated with the number on a piece of paper which was covered by a clear part of the cover when you closed it. The best was erasable, but I wouldn't push it as it never got completely clean. I can't remember who made it now.
@lumsdot
2 жыл бұрын
i guess you could also use a photo transitor to detect the pencil marks
Приставка телефонная "Трель-2" выпускалась предположительно с 1983 года. Служит для запоминания и автоматического набора любого из 40 номеров АТС. The telephone prefix "Trel-2" has been produced presumably since 1983. Serves for memorizing and automatic dialing of any of 40 PBX numbers.
@Alexagrigorieff
2 жыл бұрын
Prefix - это приставка к слову (грамматика). Здесь правильное слово appliance.
@ua4avb18
2 жыл бұрын
83? Помоему с начала 70х
I worked with some Bulgarian engineers in the 1980s (here in the UK), each engineer was accompanied by a party member (veiled threat!). They were brilliant (nearly as bright as Michael here :), but held back by inferior technology and political structure! Electronic/trade mags would go missing, and I was asked if I were able to get them something?! After careful and worryingly listening, I discovered it was - record styluses, phew. Back home, they used them as currency? Very sad to experience these brilliant people being paid and respected so lowly. My wife and I accompanied them (on the firm) to nights out in London town - they were completely and overwhelmingly gob-smacked :) Such delicious decadence :) It wasn't long before 'the wall' came down :) A happy, healthy and prosperous new year to you.
@Engineer_Stepanov
2 жыл бұрын
True.
@JanicekTrnecka
2 жыл бұрын
Getting a record stylus back then in eastern bloc - pure unobtainium.
I just love the look of those transistors. A work of art in itself.
@pvladi
2 жыл бұрын
if you file the cap off they become phototransistors
@user-nz8rv8ft5q
2 жыл бұрын
Comrade, almost or probably everything that he has touched was produced in a single country in full cycle: from instruction manual to ICs.
@iamjadedhobo
2 жыл бұрын
@@pvladi I've got a pile of 2N3055 for that :)
Hi Mike, give to Sam to connect to his Strowger PBX. He may well turn it in to a programmable music sequencer too.
@TheManLab7
2 жыл бұрын
DO IT MIKE!!!
Imagine having to "program" these in an office environment 😱
@electronbox
2 жыл бұрын
Imagine Karen programming it.
@sismofytter
2 жыл бұрын
@@electronbox 😂😂 That would triple the time doing it
Your teardowns are the best. So many interesting devices that you get your hands on. The descriptions are quite accurate unlike others. Your pace is quick yet thorough, you don't waste time to teach basic electronics that everyone knows. It is good that you skip the unscrewing parts Much appreciated.
I believe the thing was designed in 1970s and produced so long just because of planned economy. I have 1980s "Виза-32" (Visa-32) which obviously was more modern design and also massively produced at same time. It uses RAM ICs for storing data. But of course if your AC power fails and you forgot to check and replace backup battery before then... well, you just need to program everything again☻
This smells a lot more like an array of very small current transformers than actual core memory to me.
@BrekMartin
2 жыл бұрын
There is core rope ROM (this) and core RAM. Entirely different concepts. Both used in Apollo craft.
Happy New Year and thanks for showing how this worked. It give an idea on how a person could make some memory for a science fair or classroom demonstration.
love that this required careful thinking just to program the numbers! Fascinating bit of tech!
Incredible! Few ferrite cores, tranzistors and TTL chips, and they made ~1kB of memory with their logic function. Simple, clever, a little bit hard to use, but you do it once. As a reward you can feel like 60'-70' computer science doctor.
Great Video! But could you please upload a scan of the manual too? Didnt find it on the Internet, i also have the same machine.
Simple and beautiful. Thank you for this video.
Nice. Fascinating to see rope core memory. I was expecting complex and hard to use system, but actually this is pretty easy implementation, and very easy to program.
Cool tech, amazing it still works. Thank you for sharing!
Checked the schematics: Logic is different NANDs and D-triggers "Interesting-looking capacitors" at 6:45 are thermistors. There is also reed/magnetic switches there(don't quite get what for) Bonus: 0.4434 g of gold (probably in diodes), 0.126 g of silver (contacts)
@mikeselectricstuff
2 жыл бұрын
Reed switches are the reed relays for phone line interface
@yanikkunitsin1466
2 жыл бұрын
@@mikeselectricstuff thanks! Do you by any chance know how this big white thing is named on PCB layout(I don't have it)? Judging that it's near a switch I suppose it's for alternative telephone exchange mode.
@Alexagrigorieff
2 жыл бұрын
*open collector NAND.
@Alexagrigorieff
2 жыл бұрын
>"Interesting-looking capacitors" Looks like K53-7 niobium capacitor, though I'm not sure why it would be in this civilian product.
@Alexagrigorieff
2 жыл бұрын
You're right, it's thermistor ММТ-4
Thanks Mike, Neat item. Sure got my brain stirring following your great analysis. Also remembering old 60's core memory boards and shipboard magnetic amplifiers for winch control.
Absolutely beautiful, what a piece of art and history.
I've always wanted one of these. They're are a bunch on ebay at the moment. Nice to see one taken apart.
That is just amazing. Its also amazing that it has a schematic and PCB layout.
That was the simplest and clearest illustration of how core memory works that I've ever seen. Thanks Mike!
@djmips
2 жыл бұрын
Note - this isn't core memory like RAM, it's Core rope memory, a type of ROM.
@McTroyd
2 жыл бұрын
@@djmips Fair point, but still illustrates the point well. I know there's a flux-shift element to the RAM, which makes a good deal more sense with this primer.
This was a lot easier to understand than I thought it would be. It's such a simple and smart way of doing it.
Absolutely amazing. Thanks.
Трель-2, чего только не выпускали, только мало у кого такое было.
@tituszx1
2 жыл бұрын
Кому было надо, сами паяли в радиокружке, вплоть до компьютеров
@TheKelikat
2 жыл бұрын
даже не знал о таком чуде, хотя и не надо было, телефон появился году в 2008. но тут явно собрано из ненужных деталей. военное смешано с бытовыми 70 годы с 80. при этом плата военная, значит делал военный завод из того что было. для гражданки они бы взяли гетинакс
I've seen magnetic core memory before but didn't know about this type of read-only programmable memory. It's fascinating! I arrived here from Sam's video - when he mentioned you it was a surprise because we met at Gaussfest recently. I don't know why I haven't been subscribed to your channel since then, but that''s remedied now. Thanks for this.
@BrekMartin
2 жыл бұрын
Yeah magnetic RAM would work, but back to needing a processor again to read and rewrite it.
Awesome, thanks for the upload :)
That is super fascinating. I love it!
The No 5 Crossbar Switch used a similar scheme in a device called a ring translator used for billing. I wired those when I worked the frame in my early telephone days.
Как трудно выговорить трель)
Was going to announce that core rope isn’t storing anyone’s phone numbers until I see the thing almost sent as a kit you have to weave the damn thing yourself haha top stuff :D not too dissimilar from old ham radio VHF that had the user wire a diode matrix for their channel selection.
Amazing, thank you for exploring that for us! What a clever bit of engineering!
@8BitNaptime
2 жыл бұрын
This is from the sad era of the Soviet shortage of jumper links.
Interesting tech. Thanks for the video.
That's weird and amazing at the same time. Crazy how behind that tech was for the time, but it worked!
Amazing! I'd be interested in more soviet era comparisons in tech. I've never seen anything like this before.
@poptartmcjelly7054
2 жыл бұрын
Did you know that in the 80's soviets made their own computer called "kilobyte" and all of the chips inside were clones. The main board was also 10 layer!
Absolutely fascinating. Mind blown.
Fascinating! Thanks for sharing this with us. Love the old Cold War era tech.
Some thoughts: I’m really enjoying reading translations of some of the Russian comments on this video, the idioms, especially in an argument are quite funny Also i was born after the age of pulse dialling, but since the phones of the time used actual dials, I imagine a device like this was a godsend for efficiency and not tearing your fingers up on a busy day like I’m told happened I wonder how expensive this was at the time, it might be a cultural thing but I can imagine outside the office, housewives and families with things like this for their friends’ numbers
For me the most unusual thing is the crosshead style screw, all the screws I've seen in soviet kit were flathead with no exceptions!
@aserta
2 жыл бұрын
There are cross thread screws, but they're for flat head screwdrivers. It's possible someone was in this before Mike.
Russians made fantastic steam irons i still have one from the early 80s in working order.
"look mum no computer" would love this
@Enigma758
3 ай бұрын
You know he acquired it from Mike and now has a few videos about it.
@grzegorzbrzeczyszczykiewic199
3 ай бұрын
@@Enigma758 😮
As a Russian-American, i seen a lot of stuff like so in person. A lot of army/military things are so interesting to take apart to see how things goes.
Fascinating! And to think my grandparents had issues programming phone numbers into their smartphones...
With all due respect sir, clearly you know far more about circuits than I do. But the pencil pointing at the old schematics was...making me nervous. Thanks for your video! New Sub!
@uhrbexer9134
2 жыл бұрын
It's like explaining a Picasso hodling a glass of red wine.
Funn, freaking, fantastic. Thanks for this pice of old and cool stuff.
In era of transition from analogue to digital phone lines, digital centrals would by default emulate analogue. Star sign was then used to tell it to switch operations to digital mode where numbers could be dialed by tone.
My best guess - it would have allowed a secretary, to connect a military commander, to a number, with out them being knowing what the number is. Especially if the phone was screwed down to the base, with tamper proof screws. Press the number and lift up the receiver once it started ringing to HQ :) Likely as not, it would have been on the separate military phone network, hence only 7 digits needed.
@eDoc2020
2 жыл бұрын
I'm sure people back then knew that they could count the relay clicks to learn the number.
@yanikkunitsin1466
2 жыл бұрын
No, regular device for reception or secretary in relatively small organisation. 7-digit was maximum local phone number length in USSR (not counting region/town codes).
Amazing device… so clever!
@look mum no computer might appreciate this
@lumsdot
2 жыл бұрын
could use it to store notes
@timballam3675
2 жыл бұрын
Yup he could connect it upto his phone system....
Quite amazing look at Soviet tech in 1985. Core memory was practical. Nice to see you have it working too!
@thelittlebigoneru
2 жыл бұрын
it was VERY strange device even from standpoint of 1980 soviet electronics engineers :) kinda pun toward all of the rest of progressive humankind :) 😁
I *think* the Cisco/Linksts PAP2T can cope with pulse dial. Happy to send you one over configured to bridge to SIP or have a crack myself at actually getting it to make a call
Fascinating bit of kit, 1 number for home and 39 for the Kremlin, love the mug you've got there ! Happy new year to you and and your's....cheers.
One box to ring them all :) Nice cup by the way, Mike.
Literally a piece of space technology (the rope core memory) on your desk, amazing! I wonder if they advertised it as such at the time.
That is really fascinating! 😀
i love how these looked
Great content as always, any chance of making the schematic available on-line?
@mikeselectricstuff
2 жыл бұрын
electricstuff.co.uk/trill2.pdf
I need those cores. I’m really intrigued by Core Memory. I want to weave my own memory modules. It’s hard finding good quality examples of how core memory worked. Christian From “Play With Junk” Channel sent me a DIgital/Harris J11 Ceramics. By far my favorite CPU. Thanks for your time explaining this piece of nostalgia. God Bless.
Very interesting, I thankyou
Apparently it was late 70s. No idea how it remained in production till 95.
@michaireneuszjakubowski5289
2 жыл бұрын
It's the fate of most late combloc era utility products. For example, the most popular light-duty truck around in Poland in the 90s was introduced in the 50s, received the last lift in 1970, and was then made until 1998 with basically no further changes. It might have had to do with the depression and chaos of the 80s. A lot of modernization/development programs were nixed at that time, both in the USSR and in other combloc countries, across various fields.
@uhrbexer9134
2 жыл бұрын
Indeed, the motto was never change a running system. That was ensured by overboarding bureaucracy, lack of motivation and scarcity of almost everything. Like in GDR the Trabant car, whose body was cased in phenolic rag and cardboard from 1958 to the end of production in 1991.
I think for digit select they could have used just 2 wires per core. Have one wire pass through all the cores into the common emitters and selecting digit by passing the same current in opposite direction through that 4 rings.
I always said dealing with soviet technology requires a very specific mindset, especially if you are used to western stuff. Living in a post-soviet country I have encountered a lot of their tech as a kid, but only recently came to realise just how different some of it was from the equipment that trickled in from the west in the 90's. Great video!
Anyone knows older Siemens Hicom Phones? The standard phone for the lower ranks had 4 or 10 buttons to store numbers. There was an additional boss pad available with 20 or 40 extra buttons to make the owner feel important. So this soviet device seems to be the equivalent to that, as the owner of a phone in soviet times was already very important, but only the most important people who could afford or were acknowledged to buy this device would be able to dial a number with one fingertip instead of bleeding fingers.
mind blown........
Wow! That was surprising.