Z80 Computer - Part 7 Keyboard Layout

In this part, I start to think about making it easier to create larger programs by making use of an assembler program. I also look at how to send a file to the EEPROM via the TommyPROM programmer.
I cover a couple of recent video comments and then start thinking about keyboard design.

[@nand3kudasai]

feedback: i really love your style of videos. very clean no noise, no animation, no intro, etc (except the subscribe bell which i find annoying). also i admire you, this project is a child dream of mine. im not sure i can devote to it now, so watching you is very satisfyind and you answer the questions i have that i always wondered 'how does this actually works low level'. doesnt matter if youre not an expert, your mistakes are also very educational, specially from a 'life' pov.

[@ocukor1]

Your videos are great, and you explain everything very well in plain English. Don't pay attention to grumpy cats telling you that you're not an expert. You don't have to be an expert to teach what you know. Ben Eater is not an "expert" either. Anyway, who is an "expert" in Z80 these days? These are hobby chips. Engineers and researchers who design new stuff probably touched up a little bit on Z80 in college and that's it. People, get some sense into yourselves please...

[@elektron2kim666]

I wrote a bit "assembler" for my ZX-Spectrum with DATA sentences like x,y,z,201 (all numbers) in Basic as a teenager. It concluded with a racer program reading the road map (some random thing to make in Basic before starting) and the machine code took care of left/right and writing to the screen and collision. "The race car" was 8x8 pixels and also just a character to read from Basic data. It crashed the ZX-Spectrum 100 times. The speed gain was 100 times better and I had to go to a computer school in the end of it. There we went back to the past in my opinion. At least I got a job for a short time and therefore it paid off somehow.

[@pocketscience911]

General comment re this series - you're doing great! Keep it up, it's immensely interesting and useful!

[@SteveRaynerMakes]

thanks. taking a bit of a break at the moment, but will be back soon with more videos.

[@tuppyglossop222]

Just binged through the series and subscribed. It’s interesting following what you are doing, with the added bonus of learning something new.

[@SteveRaynerMakes]

Welcome aboard!

[@SimonParkes]

Been looking forward to this video, thanks Steve, and thanks for the board, it eventually arrived :)

[@jaspervandriel8465]

Really cool to see the whole progress! Thanks so much for sharing.

[@SteveRaynerMakes]

Thanks for watching!

[@phils_arcade]

Great set of videos. I'm currently working my way through repairing old school arcade PCBs, Space Invaders, Galaga, Hunchback, etc.. and this well fits into that. Have subscribed and keep up the great work :)

[@Yeoman35]

You might like to look at the layout of the Periboard-409. It has a 75% size, I bought the UK, PS/2 version for one of my projects.

[@myrpiesite]

Another great video! Cannot wait to see the final product!

[@SteveRaynerMakes]

Thanks. Might take me a while. I think there are going to be some difficult challenges ahead but it's fun and keeps me out of mischief.

[@dmitrydumanov5665]

Хорошая работа! Жаль что я плохо понимаю английский, поэтому смотрю ваши видео через переводчик, мне очень нравится то, чем вы занимаетесь)

[@SteveRaynerMakes]

Спасибо

[@bblevins]

loved your video! Can't wait to catch-up on all the parts. An idea for your keyboard layout... Move the \ key next to the ] key and use a smaller enter key. That would allow you to arrange the arrow keys as a common inverted T.

[@kylecampbellweb]

Fascinating!

[@benhetland576]

I remember from back in the days that utilizing interrupts were crucial for a responsive design. (Kids these days really don't know what _responsive_ actually means.) A polling keyboard "driver" was used on CP/M for the Osborne 1, which also used the Z80, and if you were touch-typing it wasn't very difficult to get ahead of the computer's "responsiveness". The result was lost key presses and a lot of annoying spelling errors.

[@nand3kudasai]

i know is late for this comment, but i personally think that having F keys on a retro pc is actually *more* useful than now. for once, thats where they where created, but also it allows you to call to 'operative system' calls (maybe interrupts or something. that can bypass each program. (hard for me to think of an example but one of them could be reset, or halt, or something). but also gives you shortcuts on apps without having yo to do more complicated key combinations.

[@benhetland576]

I would either swap the up&down keys to make them more consistent with similar conventions like vi's HJKL; or I would put the up arrow where you had the \ key, to make a semi-arrow layout. The \ would have to go where you didn't like it (left of Z), leaving a free spot to the right of SPACE, or you could be bold enough to move the \ one row down to that spot.

[@Chriva]

It could perhaps be strange to you but we have a small shift key on the left side in our layout (to be able to fit another special character). Would it be too strange to perhaps make that one smaller and move the fn up one step so that you can have two identical control keys? Another idea would be to replace caps lock with something else since it's virtually unused except for L O U D mode in chat forums :)

[@microhobbyist]

I also made my own keyboard PCB, 8x8 matrix, with diodes. I presented the PCB in one of my videos. It was a long process to do the PCB like I wanted to. I haven't soldered the components yet. Hope it works. LOL

[@SteveRaynerMakes]

I've just caught up on your videos. I don't know why I didn't get notified. I'm subscribed and have clicked notify all. Maybe I just missed them somehow. The keyboard PCB looks really good. I never expect anything to work the first time, although often they do. I'm sure it will be fine.

[@knghtbrd]

You'd have made your decisions by now, but: Keycaps: DSA and XDA. Profile is same row-to-row which allows more room for rearranging what's where. You could've implemented PS/2 on the Z80 directly OR used a UC, but your reasoning for the latter is sound-ish. More on that in a minute. Maybe unique viewpoint: Some classes of chip (e.g. video) are unobtanium new. NOS maybe, but most likely used pulls. There's enough to supply replacement parts until someone makes a popular project … MOS 6560 is > US$100 last I looked because someone created a VIC-20 kit. UC can emulate a video or sound chip and IMO that makes sense today. Save the "cheap" used pulls for the low-demand repair market. Bonus of UC over CPLD/FPGA: Porting to a new UC is easy, some old retro project HW is dead now because the FPGAs they _needed_ are too rare now. A UC for PS/2 can likewise make sense, after all IBM used one all the way back on the IBM PC. The thing is, like you said, using one that's more powerful than the machine you're building … ehh, feels like cheating. Only way I can justify it is if it really increases the convenience and cuts the costs. If you design a matrix keyboard interface and test it even just on a breadboard using some of those keypads in every Arduino sensor kit wired together into an 8x8 matrix … you have a test circuit. I'd do this for keyboard, eventually mouse, and probably SNES gamepads. And then I'd replace all three of those with a UC that could host a basic USB keyboard, mouse, and Xinput-compatible SNES gamepad. Here's the circuits you can build … or the UC circuit you can just program. Your choice!

[@pevkh8359]

Can I get The link to The key set you bought

[@SteveRaynerMakes]

Checkout the description in part 10 for all the links .

[@johnbrogan6583]

is your EPROM programmer similar to the scratch built one that Ben Eater used?

[@SteveRaynerMakes]

Similar, but not the same. Mine uses the TommyProm design which can be found here: tomnisbet.github.io/TommyPROM/

[@johnbrogan6583]

@@SteveRaynerMakes thank you

[@pevkh8359]

11:30 You need atleast 4 Funktion keys

[@SteveRaynerMakes]

What would you use them for?

[@SteveRaynerMakes]

Still lots of possibilities. We have the Fn key. So we could use Fn+1, Fn+2, etc. We also have the Alt key. I agree more keys are better, but I'm trying to keep the design minimalistic, but still useable.

[@pevkh8359]

9:45 Can you pleas put the Bredbortport to some kind of Expansion port

[@SteveRaynerMakes]

I'm not sure what you mean.

[@pevkh8359]

@@SteveRaynerMakes I want to have an expansion port on the computer, so I thougt abaut using The long black conector that was used to conect to the breadbords in the Begining.

[@SteveRaynerMakes]

@@pevkh8359 Yeah an expansion port is a good idea. I was thinking on my final design I will use a PCB edge connector like it was done in the old days. But for now, that long black connector is proving invaluable for prototyping with breadboards. It's perfect because it's 40 pins long so I've connected all 40 of the Z80 CPU pins to it.

[@edabean007]

i know this is more of a blog / demonstration of your adventures but do you by any chance have a schematic of your z80 computer in its current state? or do you think you will try to create one when your computer is in a more complete state? Thank you for the content so far! i have been enjoying watching your z80pc come to life :D i would love to send you one of my salvaged FDD's for it but i live way too far away

[@SteveRaynerMakes]

I currently have bits of schematics. I'm not sure if they are 100% up to date. I'll try to look over them and put them on my GitHub repo soon.

[@pevkh8359]

9:46 What softwere is that

[@SteveRaynerMakes]

Fusion 360

[@JarppaGuru]

22:27 i would be first who completely change how qwerty keys look. annoying 1/3 and 1/2 here. why not all keys 1/3 or 1/2 LOL.and cursor would key like cursor keys. if nothing works then keep cursor keys like they are and add F keys where home/end pageup/down to get some extra keys xD and if do own keyboard it not have to be any layout its your machine. it might be so good it come default in 20 years LOL

[@pikadroo]

Part 7 isn’t a great title

[@orrenjenkins289]

its accurate

[@SteveRaynerMakes]

Fair point and it probably doesn't help with the KZbin algorithm. Maybe I should change all the titles.

[@catgirlQueer]

@@SteveRaynerMakes personal recommendation from other series I've seen: put something about the content itself in there, so instead of having to figure out in which part you added the numerical displays you can just see "oh Part 4: Numerical Displays" or something of that nature

[@pevkh8359]

22:28 Meinung: -Were is the Halt key -Weres a key to do a soft reset incase it crasches -Were are the special Charecters like ├│¬... -Were is the clear Screen buton

[@SteveRaynerMakes]

Back in the day it would have been common to have a 'Break' key. But I can remember spending many hours trying to come up with ways to disable it. We have the Ctrl key, so we can do things like Ctrl+C to stop a running program. Good to get your thoughts though, and would be good to hear for others too.