Happy to see that somebody used the Zilog PIO for once, always a bit piqued to see retro designs using a 8255

It's a bit unfair to say that the Z80 is hard to use. Sure, microcontrollers are simpler for control tasks like these, but you can't make a proper computer that loads and executes code from memory with most microcontrollers. My first computer (the speccy) where I first started learning programming, used this little chip as its CPU. As a result I'm exceedingly fond of it :)

love the old stuff brings back memories of tech school in 1977 using 7400 series chips to make a clock or simple computer. that took quite a few 7400 series chips. thanks

Lol - can now do same with a couple of Arduino's and shields - kids of today will never have the joy of fault finding on this scale - great to revisit these old projects - I have a box full of them in my loft ! Great video - thanks

Good old Z80. I wrote a Z80 emulator & debugger on a VAX Minicomputer while I was at Uni in the early 1980's so I got to know that CPU quite well :-) Thanks for bringing back those memories. Also, your Z80 boards etc look like one of my later projects using 6809. Still in the loft somewhere.

I still use enamel copper on all of my one off microcontroller or accessory boards today. Part of my old 1980's Boeing R/D work when we weren't wire wrapping

And programmed without RAM! Only using the Z80 internal registers as storage. That's impressive! Of course a big advantage of the Z80 is its shadow registers.. With a bit of creativity, it gives you actually a relatively large amount of storage. And beautifully built as well!

Just watched the video... Boy do it bring back memories !!! I started on the Intel 8008..

I really like your PCBs ! Extremely well done. I wish i would have all the knowledge that you own.

Crazy! I cannot imagine the time required to solder and even to debug. BIG RESPECT to all who got us the road down to Arduino / Attiny85 simplicity.

Amazing ! I'd love to rummage through your old electronic gadgets. I remember having a lot of those 5-1/4 floppies. They failed so much you would have to have lots of them as backup copies.

Wow, a lot of hard work went into that, makes me appreciate modern microcontrollers! Never knew about this vero-wire stuff, pretty cool.

Z80s are alive and well! They are still used in every TI 83 and 83 graphing calculator made.

Hi, Julian. You've seem to had an interesting career path. Nice work.

Magnificent! Thanks for the tour, and a few flashbacks too. :)

The Z80! I absolutely love that little CPU, thank you for doing this video :D

Really like those wiring harness! Did a bunch of that in my life

just bought 5 reels of that enamel coated wire, looks very neat and tidy and is just what i need!!

I have to say WOW. very good and all your own design? well done.

Aw...the good old days...thanks for sharing... Bud...

Back when you were designing this I was trying to design a Z80 multiple CPU. Just didn't have the time and always going around the world. I did pick it up back in the 90's but switched to the CPU of the time which was 386. I got the OS written as I thought that would be the hard bit but I was defeated by a hard drive crash and bad tape and floppy backups. Wished I had a second hard drive controller if it but it was on the pricey side then. And so the project died.

Good old Z80 times. If you are really a Z80 nerd then you know what this is off your head: 21 00 00 11 00 40 01 00 40 ED B0 C9

The good thing about Z80 is that there is instruction which the engineer who design it didn't know it exists. Like.... Op code shift DD or FD and then using single byte LOAD instructions, not documented in any manual. Because they didn't imagine that possibility. so you can "LD b, IYh" or " LD c, IYl" or , LD a, IYh .... LD a, IYl and just handle the Indexes registers as any other 8 bit operand. This is because "shift opcodes" which enables new opcodes tables are just, by exameple: Exchanging for only the next instruction IY instead HL = FDh Exchanging for only the next instruction IX instead HL = DDh while EXX and EX DE , HL does the exchange but permanently. what are exchanged? the ENABLEs signals to the registers, So, BC DE HL can become BC' DE' HL' and the resulted HL or HL' can become IX or IY also, AF can become AF' . So there is like five control flipflops.

thanks for sharing your fabulous knowledge! 😊

Nice vintage board, liked the driver board.

This is a great video. Thanks for showing your Z80 serial light controller boards! The Z80 isnt dead but still in wide use. I am currently learning Z80 assembly on a Micro Professor Trainer board that my University kindly let me have. I'm having a lot of fun learning assembly which is something that I wanted to do since having a ZX81 back in the 80's and am in the process of getting a 2x16 LCD interfaced to the on board Z80 PIO. It isn't easy but its excellent fun. :)

That's a neat prototyping method!

Work of art!!

Nice work!

the enamel covered wire is also part of the Road Runner wiring system

I still have my first computer, an Osborne Executive, which used a z80 processor and came with 128K of RAM in the box. Somewhere I have a board that somebody sent me that would allow you to replace the original memory daughterboard with different parts (people also did this by piggybacking the chips one on top of another) and end up with 512K, which could give you a ramdisk, printer buffer, etc. I've never populated that board. I also have a ton of chips, both in this family and in the 6500-series family, which has its enthusiasts as well, and I used to think fairly regularly that I was going to build some stuff with some of that but somehow never got around to it. These days I'm seeing all the nifty stuff that you're doing with arduino boards, and am thinking about acquiring some of those to play with instead... :-)

Cool video! Somewhere around here i still have a schematic laying around that uses only 7400 logic chips to send a selectable command over UART. (my challenge at the time was creating a uart transmitter without special chips or microcontrollers)

that's a very tidy and small board, very well engineered

I am thinking of trying to build a Z80 board as I was a bit young the first time around. Yours looks like quite a project must have been a lot of work. I remember back in the day using the pens to draw the tracks and also those transfers for the IC pads. The joy of covering the table cloth in ferric chloride and accompanying clip around the ear. why your obsession with power banks LOL Regards Chris

I actually stumbled across a Z80 recently. I bought an old arcade poker-machine and the brains of it is a Z80. I'm in the process of finding out which of the supporting chips is faulty. I'm only getting random sprites on the screen. Not an easy task with my oscilloscope packed away. Anyway, I'm hoping to learn plenty while doing it. The Z80 predates my world of microcontrollers. I started with pic-processors.

Very interesting!

I have a board similar to that from 1986 I built for central heating timer using the 50 hertz mains has an interrupt for the clock. a lot of work compared to today's microcontroller. oshonsoft do a very good simulator for the z80 along with today's microcontrollers.

Very cool video Julian, lovely to see some old school Z80 stuff. Would love to see the code if you can manage to retrieve it from that floppy!

I loved the Z80. No refreshing of dynamic RAM (all done by the processor for you !), Expansion of the 8080 / 8085 assembly code, and very soon 'C' became available, I used to work for the British government, did you do too ? I've never met anyone else who used those Vero wiring pens before . They were so damn fast to use for prototyping (except when you made a mistake and you had to unravel yards of the stuff !).

Far out dude... Nice work

I remember the Z80 well, running CP/M or MP/M on the S-100 bus.

Nice, my father used to program the Z80 with assembly language!

Hello Julien. At 6:25 you mention the Plastic Cones. Would you be able to track them down at Mouser or somehwere else? Also the copper wire, i did not understand exactly how you call them, but understood how it works. I am very interested as i soon will start on a 8086 project. Also for your "pcb etching" i have special paper in my laserprinter. i print my (diptrace) layout onto it and then use a t-shirt hotpress at 266°F for 3 minutes to put the layout onto the pcb. after that i wash it with warm water off and off we go into the feryd chlorid bath. fast and easy.

Yay! I really enjoyed this video Julian, thanks! I am in the early process of designing a Z80 based computer and this is really inspiering. Do you have any assembly code to show of any of your Z80 projects? Maybe you could do a video on assembly programming? That is kind of relevant today even on the AVRs and PICs. I have only written assembly for AVRs. Perhaps modified some assembly for PICs.And debugged some Z80 assembly in emulators. We also need to teach the AVR-kids about the Von Neumann architecture and about being able to execute instructions from RAM. Looking forward to the next installment of "Retro Electronics" *wink* Thanks again Julian!

plastic pillar bit, I nearly went to have a go but didn't start on that but I did wirewrap and even today wirewrap still around... ask the BT?I was going to learn Z80 program but I never did till Arduino came to me... nice and easy.

Love it

very interesting, i would love to see a video of you exploring that floppy disk's custom encoding of sort you described - would be really cool to see that in 2015!

There are no Zed 80s on the boards Julian. They are Zee 80s as it is an American name. :-P Zilog is the company that designed them even though some of the first ones were made by Mostek because Zilog didn't have a plant ready to make them. You still can find them buried in all sorts of things.

Hello I enjoy your videos and would to see if you would make some videos on the assembly language.

Are those "plastic cones' common to fine enamel wire wiring? I have never seen this technique before on strip-board, it seems to keep everything quite neat.

Nice.

Beautiful! Those plastic wire cradles/organisers could be 3D printed for home use easily.

Epic fail Julian. The trace on the CRO did not change colour in sync with the light controller :) I think calling the ZS80 a microcontroller is not quite right it is probably more correctly called a microprocessor and likely predates anything we would recognise as a microcontroller. I certainly recall using the Z80 in a computer long before I was messing with 16F84 pics. The fine wire you called vero wire was known as wrapping wire here in Aus. Still pretty useful today if not in it's intended role

Hey nice project, it reminds me my old Commodore 64 days! :-) I'm wondering how long it took you to build that, especially that long one with the blue wire is all over it. :-) I have a couple questions, speaking of wires, that wire you used underneath the board enameled copper strand, I've never used that but, I'm curious cuz I see you crossing wires over top of each other and not worrying about it shorting out? I know you said it has enamel on it, but couldn't it be accidentally melted wit heat and causing shorts from say, when your soldering it or anything around it? That is kind of interesting wire because if that is the case I like to use some of that from my own circuits that I'm building but I've never heard of it. My second question I know you have a different scope than I do, mine is a Siglent and I'm curious as how you got it to only grab one pulse signal and hold?? Is that just using the AUTO button? I know mine supposedly does that but I just don't know how to set it up to grab one specific signal length and to stop automatically after for example, one pulse.

Hey Julian you know what be cool to actually take a modern micro processor and build like a retro setup like this video of yours to do something like this would be nice.

That wire you spoke of where the enamel burns off (I think you called it varo wire), can you tell me the proper name or proper spelling. I've used magnet wire and it's a pain to clean the ends before soldering. And plastic insulated wire is often just too thick. I've been doing a search but so far, have not found it.

Nice :)

I never saw VeroWire before, it looks very neat, but I guess you have to be certain about what you are doing, redoing one wire would mess up the beauty for the other wires.

"the z80 became old and unloved" well the z80 was before my time, but my first game console was a gameboy color (got one when all the cool kids had advanceSP), and recently I started developing software and hardware for it, and got kinda obsessed with the z80 (which the gameboy cpu is derived from). I was surprised to find Zilog actually still makes them in the original form factor (while also having developed z80 based modern microcontrollers w/ internal ram/flash/peripherals/etc, but that's lame, if i want that i could just use an AVR :P), and a bunch of different interesting companies make compatible stuff (e.g. I got a bunch of flash chips that fake the pinout of a parallel SRAM from Samsung of all people 0.o, and pin compatible self refreshing DRAM chips etc; very nice, essentially both are parallel addresses+data+chipselect+clock+writeenable you just stick on a bus and they just work, no ram refreshing or high voltage flashing magic etc required but also no modern fancy but hellish incompatible spi or i2c which means instantly works with the z80 and I don't need strange device specific flashers but can essentially use a gameboy cartridge reader/flasher I built to interface those too). gonna build a computer with it with my own bios and everything BECAUSE I CAN :D so don't worry, those jewels are still very loved today. and yes I know I'm crazy :D

Oh yes. Been there, done that. Much prefer the Arduino for projects nowadays. Far too easy to code and send data through Bluetooth to remote devices. Ah the good old days. Feeling old and creaky now . . .

excellent video. i was born a little too late to know, but was the z80 just an ALU

I found 1 in my workshop :D

What did you use for the switches?

oh last thing, let frame your things, i.e. box it with glass on front. cool work!

Good old days! ARM seems to be all the rage these days. 32bit microcontrollers truly scare me. I mean where do we draw the line?

ah those were the days :) I used to build stuff like that, though it was always the 6502 for me! LDA $00; DEY; STA MEMTOP, Y; JMP [loop]...

What is used to produce and print the PCB's?

Julian, can you show how to program the Z80, and make a simple blink program? It would be fun to give new life to the Z80..

why was it necessary to have zero crossing detection on the lamp control boards?

I'm wanting to fix a circuit board with a new capacitor, does it matter which way round the capacitor goes?

I'm actually slowly making something similar that runs off arduino and rgb leds

muy buen video pero KZfaq es un asco el video empezó bien y luego se empezó a pausar, lo quite y puse netflix en HD y fue muy bien regreso al video y se sigue pausando, KZfaq eres un asco

Julian, what is the correct spelling of your first name?

I love using the z80. I use home made z80 computers.

The Z80 is a great processor for the project because arduinos and stamps didn't exist back in the 80s Ha!

I see no RAM, not even a pair of 2114

See avatar ;) Z80 led board.....

Waching this makes me want to play around with logic, rather arduinos and stuff.