WEBVTT 00:00.000 --> 00:15.000 I would like to show you the last Z80 computer ever made, at least for some definition of 00:15.000 --> 00:17.000 computer. 00:17.000 --> 00:21.000 And for some definition of made. 00:21.000 --> 00:25.600 Because the 80 computers are still being made today, you can get one for one hundred 00:25.600 --> 00:27.600 per a few euros from Amazon. 00:27.600 --> 00:30.600 And it will be shipped tomorrow for free. 00:30.600 --> 00:36.600 But the only reason this is using a Z80 is for compatibility reasons with a long family 00:36.600 --> 00:40.600 of previous machines that stretches back to the late 80s. 00:40.600 --> 00:45.600 So if they build this today, they would probably use ARM or X5. 00:45.600 --> 00:47.600 So that's not what I have in mind. 00:47.600 --> 00:51.600 And of course, you can also find the Z80 in embedded systems. 00:51.600 --> 00:56.600 And in hobby machines made for fans of retro computer. 00:56.600 --> 00:58.600 So for people like you. 00:58.600 --> 01:02.600 So again, that's not really what I would like to talk about. 01:02.600 --> 01:11.600 What I really want to know is when was the last time that somebody sat down to design a completely new computer 01:11.600 --> 01:15.600 and he tectr for the general public. 01:15.600 --> 01:20.600 So not for you. 01:20.600 --> 01:25.600 And he decided that the Z80 was the best match for it. 01:25.600 --> 01:30.600 So I asked tragedy. 01:30.600 --> 01:32.600 And it showed me this. 01:32.600 --> 01:34.600 Which is a nice guess. 01:34.600 --> 01:38.600 But of course, tragedy is wrong. 01:38.600 --> 01:44.600 Because two years later, we got a nice Z80 based pound-top, for example. 01:44.600 --> 01:52.600 And yet, two years after that, we got this. 01:52.600 --> 01:54.600 A sweet call mail station. 01:54.600 --> 02:01.600 And this is the last Z80 based architecture that I was able to find. 02:01.600 --> 02:04.600 So what is the mail station? 02:04.600 --> 02:11.600 Well, in the 90s, there was a choice to build the built machines that were labeled as 02:11.600 --> 02:16.600 internet appliances to make connecting to the internet easier. 02:16.600 --> 02:26.600 If you ever wanted to go online on Windows 95, you know that it's, let's say, not very easy. 02:26.600 --> 02:33.600 So for many people, it was a standing block to go online and use the web or the email. 02:33.600 --> 02:39.600 So many companies built specialized appliances that let you just plug it in, 02:39.600 --> 02:42.600 turn it on, and it would work. 02:42.600 --> 02:50.600 So the official slogan through the main station was email made easy. 02:50.600 --> 02:56.600 You just plug the machine into your phone line. 02:56.600 --> 03:05.600 You turn it on, it would dial to the ESP phone number and you could send and receive emails. 03:05.600 --> 03:11.600 For some reason, they renamed it very quickly to email without a PC. 03:11.600 --> 03:16.600 So I guess that was not that easy after all. 03:16.600 --> 03:18.600 But that's the main station. 03:18.600 --> 03:26.600 And if you look at the hardware specs, it has a blazing fast Z80 processor running at 20 megahertz. 03:26.600 --> 03:32.600 A lot of memory, a modem, and it has even a printer port. 03:32.600 --> 03:38.600 So you could not only read your emails on the screen, but actually print them out. 03:38.600 --> 03:43.600 And it will prove very useful in a few minutes. 03:43.600 --> 03:50.600 So because it's a specialized machine, it stretches a little bit the definition of a computer. 03:50.600 --> 03:57.600 But at least for me, if it works like a computer and it works like a computer, then probably it's a computer. 03:57.600 --> 04:05.600 And the most important reason why I think so is that because it can run custom applications. 04:05.600 --> 04:15.600 So you are not limited just to the email sending receiving firmware that's on the machine, but you can also run your code on it. 04:15.600 --> 04:19.600 And if you can run application, then of course you can hack the machine. 04:19.600 --> 04:24.600 And that's the most important thing you do with the computer. 04:24.600 --> 04:27.600 Let's do it. 04:27.600 --> 04:34.600 First, I would like to show you the official method of running applications on this machine. 04:34.600 --> 04:40.600 If you power it on, you can see a little Yahoo icon. 04:40.600 --> 04:48.600 And if you choose this many options, you get a list of various information channels. 04:48.600 --> 04:52.600 In this case, these are top stories and TV types. 04:52.600 --> 04:59.600 Also subscribe to weather forecasts, stock quotes, horoscopes, these kind of things. 04:59.600 --> 05:05.600 And this would be updated on your machine every day. 05:05.600 --> 05:10.600 So if you choose top stories, for example, this is what you get. 05:10.600 --> 05:19.600 Because it's an American machine or the top stories about mass shootings. 05:19.600 --> 05:29.600 And you would think that this is some kind of America language that is used to display this information on your screen, but it's not. 05:29.600 --> 05:35.600 It's a bit map. 05:35.600 --> 05:47.600 And those top stories icon that you just clicked is an application written in the 80 assembly code that displays this bit map on your screen. 05:48.600 --> 05:55.600 So you could have any kind of application written and you could just run it the same way. 05:55.600 --> 06:08.600 So the way it works is if you subscribe to an information channel, Yahoo sends you an email every day with an updated application. 06:08.600 --> 06:34.600 Your computer downloads this email and without telling you, it does not put it in your inbox, but it just extracts the application and puts it in the Yahoo folder. 06:34.600 --> 06:42.600 And this application can run any Z80 codes. 06:42.600 --> 06:52.600 And it because it's as 80, that's of course no memory protection. 06:52.600 --> 07:01.600 So as you should know, the first rule of image security is do not open unknown attachments. 07:01.600 --> 07:14.600 But it does not apply to the main station because in the main station, you don't open the attachments, the computer opens them for you. 07:14.600 --> 07:20.600 So of course, the creators of the machine thought about some security issues. 07:20.600 --> 07:26.600 So there is some kind of checksum that must be correct in order for all these to work. 07:26.600 --> 07:30.600 So they even find a patent where you can read about all these. 07:30.600 --> 07:37.600 So I was not really familiar with this simple desk version of encryption. 07:37.600 --> 07:43.600 So I asked John GPT how easy it would be to crack it. 07:43.600 --> 07:50.600 And the answer was not very much. 07:50.600 --> 07:56.600 So what you could do? 07:56.600 --> 08:04.600 What you could do is write your application and send yourself 1224 emails with different checksums. 08:04.600 --> 08:10.600 And one of them is guaranteed to work. 08:10.600 --> 08:13.600 There's only one tiny little problem here. 08:13.600 --> 08:18.600 You would need to have an email account configured on your station. 08:18.600 --> 08:25.600 And if you try to do that, you may get the screen. 08:25.600 --> 08:30.600 So I called this number. 08:30.600 --> 08:33.600 And I was put on hold. 08:33.600 --> 08:38.600 It was half an hour of my life that I will never get back. 08:38.600 --> 08:47.600 And finally I learned that support for the main station stopped about 20 years ago. 08:47.600 --> 08:49.600 So the dial-up numbers don't work. 08:49.600 --> 08:51.600 The servers don't exist anymore. 08:51.600 --> 08:55.600 They will not configure the email address for me. 08:55.600 --> 08:59.600 But don't worry, we are not done yet. 08:59.600 --> 09:07.600 When the machines were released to the market, some enterprising hacker disordered the wrong sheep from the mainboards. 09:07.600 --> 09:13.600 And when it analyzes, he found those ASCII strings. 09:14.600 --> 09:21.600 So those strings suggest that there is some way to update the software on the machine. 09:21.600 --> 09:28.600 So a couple of guys got together and they started analyzing the code around those strings. 09:28.600 --> 09:34.600 And they came up with nice diagrams that show how the code works. 09:34.600 --> 09:39.600 It's really easy to follow and there's just 10 pages of it. 09:39.600 --> 09:49.600 So if you look at the diagrams and analyze how they work, it's basically this. 09:49.600 --> 09:52.600 And the one ever used one of those? 09:52.600 --> 09:54.600 Yeah. 09:54.600 --> 09:55.600 Yeah, exactly. 09:55.600 --> 09:59.600 So the main station has a pointer port, right? 09:59.600 --> 10:08.600 And a smart company named LappLink came up with a way to use a pointer port for bi-directional configuration. 10:08.600 --> 10:15.600 Because in addition to the data bits, the pointer port has also some lines to which status back from the pointer later. 10:15.600 --> 10:22.600 The pointer is busy, the pointer is out of paper, the pointer is on fire. 10:22.600 --> 10:28.600 So if you cross-connect those status bits with data bits, you can send data back and forth. 10:28.600 --> 10:34.600 So using this kind of cable, you can upgrade the firmware on the main station. 10:34.600 --> 10:41.600 So I wrote a short program, which does exactly that. 10:41.600 --> 10:48.600 The only tiny little problem is that you need to upgrade the whole one megabyte of firmware. 10:48.600 --> 10:57.600 So even if you write a tiny change to some tiny function in the wrong, you still need to upload the whole one megabyte through the cable. 10:57.600 --> 11:05.600 And if something wrong happens in the middle of this process, you get a breakdown of the station. 11:05.600 --> 11:10.600 Trust me, I should know. 11:10.600 --> 11:15.600 So is there an easier way to do it? 11:15.600 --> 11:17.600 Well, there is. 11:17.600 --> 11:20.600 At least for some definition of easier. 11:21.600 --> 11:33.600 If you power on your station and press a secret key combination, you will get a nice diagnostic mini, which asks you to choose one of the six options. 11:33.600 --> 11:35.600 Don't do that, of course. 11:35.600 --> 11:40.600 But press another secret key combination. 11:40.600 --> 11:55.600 And you will get a hex viewer, which allows you to view the contents of the flash chip that holds all the user data and settings. 11:55.600 --> 12:01.600 And using yet another secret combination, 12:01.600 --> 12:07.600 turns the hex viewer into a hex editor. 12:07.600 --> 12:21.600 So you can write your application and enter the hex decimal codes for all the bytes in your app in the editor and then you can run it. 12:21.600 --> 12:27.600 But if for some reason you don't want to do that, you can use that instead. 12:27.600 --> 12:31.600 This is called a stage one loader. 12:31.600 --> 12:35.600 It's a program that's 64 bytes long. 12:35.600 --> 12:48.600 And because the main station film already has the ladling transfer routines built in, it uses the existing ROM to download and execute the program from the PC. 12:48.600 --> 12:56.600 So all you ever need to do is to enter those 64 bytes into your machine and you're done. 12:56.600 --> 13:08.600 And then you can upload a stage 2 loader, which is a very nice mini-driven application that allows you to upload and download data from the main station. 13:08.600 --> 13:11.600 And then you have hacked it. 13:11.600 --> 13:15.600 So what have people done with the machine so far? 13:15.600 --> 13:25.600 Well, of course, because it has a more than somebody built a nice application that allows you to dial into your local BBS and interact with it. 13:25.600 --> 13:34.600 And if you don't like the modem, that's also why if I want to do it, that's somebody built. 13:34.600 --> 13:46.600 And of course, since it's a Z80 machine, you would like to run CPM on it, which is unfortunately not that easy because it has ROM at the bottom of the memory map. 13:46.600 --> 13:51.600 So somebody built a hardware modification to put RAM there instead. 13:51.600 --> 14:00.600 And then he wrote a nice CPM BIOS and he wrote, I think, something like that. 14:00.600 --> 14:04.600 Okay, so these are some of the projects that I find on the internet. 14:04.600 --> 14:08.600 But the most important project has not been written yet. 14:08.600 --> 14:12.600 And maybe you are the one who's going to write it. 14:13.600 --> 14:30.600 If you want to do that, I created a main station function library, which allows you to interact with some such hardware functions as screen keyboard timers, interrupts, modems, stuff like that. 14:30.600 --> 14:35.600 We added some more resources, so there's an emulator here as well. 14:35.600 --> 14:40.600 It's pretty basic, but it works, so you don't really need an actual machine. 14:40.600 --> 14:43.600 You can write your code and run it in the emulator. 14:43.600 --> 14:48.600 There are some sample codes, libraries, documentation, data sheets. 14:48.600 --> 14:52.600 All you ever need to hack the main station is here. 14:52.600 --> 14:57.600 But I also have those two boxes here with me. 15:00.600 --> 15:04.600 And each box contains a main station. 15:04.600 --> 15:11.600 We've staged to loader already installed, so you don't ever need to use the hex editor. 15:11.600 --> 15:21.600 A U of P on the power supply, a lapling cable, and my email address. 15:21.600 --> 15:34.600 So if you want to get your hands on a Z80 machine and do some hacking, find me after the talk, and one of those boxes will be yours. 15:34.600 --> 15:37.600 Otherwise, thank you very much. 15:37.600 --> 15:47.600 I'm for questions. 15:47.600 --> 15:52.600 We have one here. 15:52.600 --> 15:58.600 How many did you break? 15:58.600 --> 16:05.600 Three. 16:05.600 --> 16:11.600 Three broken and he still has two to give away. 16:11.600 --> 16:15.600 And I still have eight at home, so. 16:15.600 --> 16:18.600 How the graphics work is it just a framework? 16:18.600 --> 16:20.600 It's just a framework, yes. 16:20.600 --> 16:24.600 Have anyone wrote a demo, demo scene demos? 16:24.600 --> 16:31.600 There are some applications in the GitHub repository that draw a bit up on the screen, for example. 16:31.600 --> 16:36.600 So you could count it as kind of demo, I guess. 16:36.600 --> 16:42.600 Maybe you can write about the one. 16:42.600 --> 16:46.600 Okay, over here. 16:46.600 --> 16:52.600 Can I have sound or can I convert modern port to make sound or something? 16:52.600 --> 16:55.600 I tried that. 16:55.600 --> 16:58.600 I haven't had success so far. 16:58.600 --> 17:02.600 So yes, there is a modern chip and there is a speaker. 17:02.600 --> 17:10.600 And from the data sheet of the modern chip, I concluded that it is possible to play some wave sounds. 17:10.600 --> 17:14.600 But so far, I was unlucky in that. 17:14.600 --> 17:23.600 So it could be done probably, but I can't be 100% sure. 17:23.600 --> 17:25.600 Double question. 17:25.600 --> 17:32.600 What if I tried to refresh the firmware on one of the broken consoles? 17:32.600 --> 17:35.600 And does it run doom? 17:35.600 --> 17:38.600 Okay, number two, not yet. 17:38.600 --> 17:41.600 That is a matter of time, of course. 17:41.600 --> 17:48.600 Number one, if you break your main station, it means that the code, on the main station side, 17:48.600 --> 17:52.600 used to download the firmware is not working anymore. 17:52.600 --> 17:55.600 So you can't re-flash a briefed my station. 17:55.600 --> 17:59.600 What you can do, of course, is to disolder the wrong chip. 17:59.600 --> 18:05.600 Use your eProm programmer to reprogram properly and then solder it back. 18:05.600 --> 18:11.600 Some people have reported success with doing that. 18:11.600 --> 18:16.600 You have time for one very short question, and I can ask a question of to come up to the front. 18:16.600 --> 18:19.600 Test somebody over there, I think. 18:22.600 --> 18:27.600 Where the system updates, cryptographically secured, or was it SDS again? 18:27.600 --> 18:29.600 Now, there are not cryptographically secure. 18:29.600 --> 18:32.600 You just push bites to the machine. 18:36.600 --> 18:38.600 Okay, thumbs up. May thanks, Michel. 18:38.600 --> 18:40.600 Thank you very much.