1985 Pocket Cellphone
This is a Technophone PC-105. This is the world's first pocketable mobile telephone from 1985. So there it is huh? 'I was wondering, I thought it might have been a bit smaller. But it's, it's, it does it fit into the pocket at all? Oh yes indeed. I try and carry it there all the time.' Imagine being able to carry a phone around in your pocket. OK, that's not hard to do today.
But what about in the 1980s? By 1985, Motorola had released a couple of different models of the first ever mobile phone. You could carry it around with you. But it was huge. During that year a small company in the United Kingdom decided they could do better. They designed and built the first phone that could comfortably fit in your pocket. This is the Technophone PC105. Technophone had even beaten the Japanese manufacturers to market. When the first Japanese-made cell phone, the Mitsubishi Roamer arrived the following year, the Technophone was still smaller and lighter. This phone design was so successful that at one point Technophone had a 50% market share in Europe, and were also strongly increasing in the United States as well.
The entire company was eventually bought by Nokia. Who Incorporated the Technophone design to help them develop phones going forward. The Technophone brand then faded into relative obscurity. But today I want to take this apart and see just how revolutionary this phone was. I also want to see if maybe I can power this phone up again. The first problem I have is, I don't have the charger for this phone. And there's no way of knowing the pin out of all these pins on the bottom. But the
bigger problem is the built-in battery that's been sitting inside for decades. This is very likely to be a nickel cadmium battery inside. These are prone to leaking and destroying Electronics. What an awesome phone. So it looks like it's going to have an internal battery that I'm going to have to have a look at. And I am really hoping that I can get this to power up. And it's been locally branded in Australia by Mobiletronics. On the back it comes with some instructions on how to do various functions. The Mobiletronics brand again.
So the first thing I'll do is I'll get that antenna off. Attached with a nice SMA connector there. In fact there's already a crack in the casing here. So I'll get out the mat and we'll have a closer look at getting this apart. With the four screws on the back removed, the casing is still not budging.
Careful examination reveals panels on the front that are hiding yet more screws. So I think the key to getting this apart will be removing some of these front panels to get to some screws that are not currently visible. And sure enough there's two screws here. The insides are beginning to reveal. We'll get this bottom panel off as well.
The first awesome part of the day. So let's see what's under here. Oh that just falls off. Yep we have an eprom. Wow! I wonder what's on that. Taking off the bottom panel reveals something astounding, an eprom with a clear window. It's a 27C256 eprom with 32 kilobytes of storage. The window on this chip allows you to shine a UV light down inside. This is necessary if you want to erase the chip
to reload some new software into it. This is a really unexpected find for the inside of a phone. I'm now incredibly excited to see more. So let's get these screws out and see what we've got. Carefully now. It's coming apart. Have a look at that, so many inspection stickers, all hand written.
And this looks concerning right here. It looks like there is a Varta backup battery, and it has leaked. The first thing I can see is this backup battery here has started leaking. With some corrosion on the main board itself.
I really need to get this apart to do some proper cleaning. I want to separate this back panel. Oh there we go. So this is a module that looks like it can just unplug. More handwritten stickers on the back. See we can do about this battery. I think I should be able to get this bottom module off as well. Gee, these are not attached down very strongly. I guess the casing just holds them all together. OK,
bottom module is disconnected and it has another wire linking it somewhere under that battery. Oh that there we go. So what I'll do is I'll loosen these screws over here, and hopefully that can help me get the battery disconnected. All right, let's see if I can get this battery out now
if it's still stuck. So I think these screws are actually holding the LCD onto the board. I don't know, what, well all right. So the board is now at least coming out. There we go, one battery out of the unit. So there's the two display controllers, we've got two custom Technophone chips. Everything is surface mount. I mean that's definitely bridged pins. All right why on Earth are those pins bridged with solder, very weird.
So it looks like that keypad can also unplug as well. And there's more components underneath. See if I can unplug this, only connected, here we go. I'm not certain but I don't think those pins were meant to do that. Did they come unsoldered from here? And under the keypad we've got a lot more chips. It's a double-sided surface mount board,
that's chock-a block on both sides. Damage doesn't look too bad. But that definitely does need to be cleaned up. To clean it up I'm going to have to get this display off, another two screws. Oh that display is certainly starting to leak a bit, I'll be very careful with that.
I'll do the same on the other side and just run this underneath. The rubber of this connector still feels good and spongy. I want to be able to put this back. OK, there we go there we go. I have some white vinegar here to clean this small corroded area in the corner.
The acid in the vinegar neutralizes the chemical corrosion coming from the battery. I'm going to leave this vinegar on here for about 20 minutes, so it can do its thing. When the PC105 was released, it cost 2 000 pounds. That's over five thousand pounds in
today's money. Despite the high cost, there was a market for these phones. Technophone founder Niels Martinsson was not only a gifted engineer, he was also a shrewd businessman. By 1990 he saw the changes in the marketplace and sold his company to Nokia. Nokia was so pleased with this
acquisition they continued to use the Technophone brand throughout the 1990s. I found these images of a Technophone branded Nokia 2110 from 1995. the 2110 was a flagship phone for Nokia. It's really interesting to see one with Technophone branding. And I find it strange that the Technophone brand is not as well remembered today. But this was all before the groundbreaking Nokia 5110 and 6110 that changed the industry at the end of the 1990s. 'It's the go anywhere phone, use it in the car, on the street, anywhere. Carry Technophone and you'll never miss another important call'
I also found this 2006 infographic from Nokia showing every model they had released up until that point. Despite not owning Technophone at the time, Nokia did list the PC105 and variants as part of their history. 'Very handy for me Malcolm, although it's low powered the power output is only 0.6 of a watt. Whereas the transportable and vehicle mounted models are three watt units. So this sometimes fades. So if I'm standing still I have to move around a little and if I'm in a building will I just move closer to a window, see if that improves it. OK.' The main battery is also corroding.
But fortunately the board underneath looks OK. The vinegar should have done its work by now. It's important to get all vinegar off the board after cleaning, as the acidity itself can cause further problems. Using some isopropyl alcohol I can give it a good cleaning. A quick clean of the whole board with isopropyl also helps. This main board is absolutely astounding. Almost the entire main board is covered with surface mount components. Surface mount technology was brand new in 1985.
Less than 10% of all products used any sort of surface mount components at the time. So to see such an early example of this is absolutely astounding. The board itself has 12 layers of copper interconnects. The engineering required to do this is mind-blowing for the time. It's no wonder Japanese companies were buying these phones just to tear them down and see how this was done. A 12 layer double-sided surface mount design from 1985. With two custom chips on board.
This thing is a work of art and a piece of history. I do still need to do some fixing and those keypad pins that broke off need to be soldered back onto the keypad. OK, with that all soldered, time to look at this battery. So this battery looks like it's in terrible condition.
It also looks like it was super glued back together. Not necessarily my favourite glue for this sort of thing. I really need to get this apart, so we can see how it's all connected up. Yeah, these batteries are not in very good condition. I'm going to go throw these away and I'm going to wash my hands after touching these. This battery also needs to be re-celled. Since I don't have any rechargeable double A cells, I'm going to use these non-rechargeable heavy duty dry cells. This should be fine because I
don't have a charger for this phone. So I have no intention of recharging this battery. At this stage I just want to see if this works and I can power it up. Now, because rechargeable double A's are 1.2 volts each, and these non-rechargeables are 1.5 volts each, I'll only be using five cells to keep the voltage level about the same. And I already have a bank of four connected together from an old project. So I just need to add the fifth one and put them in here.
And my dodgy battery setup is done. And it's 7.6 volts. So that should be enough to turn the phone on. All right, I'll get it together and we'll see if this thing works. OK, so display is in the correct position. That looks alright, gee there's not much clearance between that screw and those legs. Hopefully just enough. Gently push it together, come on there we go.
These RF modules also look fascinating. It looks like they have multiple boards sandwiched together. But the RF shielding is all soldered together, so taking them apart will be difficult. Maybe I'll do that at a later time. Yeah, that's not quite fitting as well as it was.
But I want to plug this in, so here it goes. Seems to be OK so far. OK let's turn this on even though there's no obvious power button. See what happens, and there we go. It's turning on. All right, fortunately it's already cracked, so that gives us a bit of room to fit that incredibly dodgy battery. But the phone is now working and we have a menu. OK so I'm not going to be able to make a call because the networks that supported these phones shut down a decades ago. And I don't have my own base station to be
able to run this phone, , yet. Pressing the menu button brings up a date the 26th of July 1989. It looks like this is the software version in the phone, and the version number is A31K-P. This matches the number that's written on the sticker that was stuck on the eprom.
It's possible the software in this phone was actually upgraded at some point during its life. I also found an ad for this model, and in it one of the features is described as having 'upgradable software, to ensure non-obsolescence the software of this Technophone can be upgraded at all times' So I think the reason the eprom is under this panel is for upgrading the software. You would take the phone back for a software upgrade. They would shine an ultraviolet light onto the eprom to wipe it. And then because the eprom is soldered into the board, obviously you plug something in and you program the eprom in circuit. Looking through the menu is quite interesting. This is often regarded as the first menu system in a mobile phone ever.
This phone has the ability to store 100 phone numbers and names. One of the more interesting options in the menu is Service Mode. and activating it changes the standby display. The numbers on the left are constantly changing and this is likely to be the phone searching different frequency channels, looking for a base station. And the number next to it is probably the signal strength. I'm not sure what the numbers and letters on the right mean. This is an unusual option to find in a standard menu in a phone. It's normally the sort of thing
that would be hidden from view. And when I find this sort of thing in a phone, it gives it a kind of engineering prototype feel to it. It reminds me a lot of the Ericsson GH337, which has a battery menu that tells you the battery voltage. Another function in the menu is the lock code. Now I'm really pleased that this phone isn't locked or that would have caused a bit of a problem. But if
you forget the lock code there is a way to reset it, and that's using a six digit security code. Now I did try the six digit security code that had been scratched onto the back of the unit. But it wasn't correct. I did however find this user manual for the Audiovox PC100. This is basically a re-badged and restyled Technophone. The user menu was helpful, but not much that I couldn't work out on my own. I kept searching until I found this text file with some very useful clues about
this phone. This text file would have been traded by phreakers on bulletin board systems in the 80s and 90s. Until it was uploaded to one of the many repositories of early hacking text files on the internet. This text file is very useful because it describes how to get the security code for this phone. First get the electronic serial number, which is usually in hexadecimal and then convert
it to decimal. Get the last six digits of the security code and then rearrange them according to this pattern. Then take that six digit number and subtract it from 999 999. The remaining six digit number is the specific security code for this phone. The rest of this text file describes how to access The NAM module in this phone, or Number Assignment Module. Hash 583 991 hash hash,
nine five three seven three nine hash. shift store 99. Enter, done. Yeah lock handset, shift, lock, power back up. There we go! This is the area of the phone where you program network specific details. Such as the phone number of the phone. Another interesting number is the Overload Class. This allowed you to set the priority level of each phone. For example, emergency services would often have
phones with a higher Overload Class, and if the base station you were near was taking too many calls and were full. A higher Overload Class number would give your phone priority over making calls over other phones on the base station. While playing around with this phone, I found some other interesting details. For example some of the data in The NAM module seems to be corrupted, and some of the options show lowercase characters. Nothing in the menu system allows you to normally access these lowercase characters. Yet here they are in the ROM. There's also some special
characters appearing as well. Including what looks to be a Japanese character right here. This really makes me want to read the eprom out of this phone and have a look at the software. Though I have no idea what CPU this runs on, and the CPU is likely to be embedded inside one of those two custom chips inside the phone. I also spotted on the other side of the board from
the eprom is this SRAM chip. This phone has two kilobytes of RAM for its working memory storage. As well as the 32 kilobytes of eprom for its main software storage. This phone is almost like a neat little 8-bit computer. And the liquid crystal display is very large for a phone at the time.
In fact it remained as one of the largest displays you could get on a phone for at least the next 10 years. Though when it came time to trying the backlight, I found that was rather hopeless. There are six green LEDs, three at the top and three at the bottom. Yet they provide no illumination and you just can't see the screen at all. I'm not really sure
what's going on there. But despite that, I do love these old liquid crystal displays. With their monochrome displays, and their beautiful fat pixel matrix characters. This phone is a sight to behold and a really amazing piece of technology from the mid-1980s. I want to thank you for watching. I hope you enjoyed this as much as I did exploring this phone. These videos take a long time to make, any support you can give really helps this channel. Even just a like and a share can go a long way. But if you just want to watch and enjoy,
then thank you! Because that's what really matters and I look forward to seeing you in the next one. Any Technophone eprom hackers out there wanting to share eprom images?