Designing a Card Slot Modular Z80 Computer
ฝัง
- เผยแพร่เมื่อ 4 มิ.ย. 2024
- This video is a broad overview of my ColemanZ80 modular computer system. It runs on a Z80 processor with all the peripheral circuitry to allow it to communicate with a terminal. This is just the beginning of this system. Examples of its functionality are included.
*as an astute viewer has noted, EAGLE's free program offers 80x100 MM (millimeters) boards not CM (centimeters). Sincerely yours, another victim of the imperial system.*
Links to Various Things-
The PCB Card Files
wrcooke.net/classiccomputer/vi...
The Backplane Design Files
github.com/colemanjw2/Coleman...
A Guide I Generally Used to Build This System:
zed80.com/Z80-RETRO/index_Home...
Ben Eater's Clock Module from his Breadboard 6502 Project:
eater.net/8bit/clock
The Serial Terminal Program for Mac:
www.decisivetactics.com/produ...
00:00 Intro
00:25 Let Me Tell You About My Computer
04:15 In- Depth Review of Each Card
10:06 Functional Examples- Displaying Text to LCD
12:26 Functional Examples- Playing Four Tones with the SN76489
12:44 Reflections and Future Plans
![ไม่ต้องมีที่ที่ให้ฉันอยู่ แต่ขอแค่มีฉันอยู่ก็พอ (Spaceless) - getsunova [SHORT FILM]](http://i.ytimg.com/vi/MuT0d_cvJkc/mqdefault.jpg)
This reminds me so much of Byte Magazine, and Ciarcia's Circuit Cellar.
I wish it was a 6502 build, but the Z80 is another great processor. This build reminds of the Altair. Great stuff!
I see a lot of these z80 or similar minicomputer projects.. I find them fascinating. My first computer was a KIM-1 6502. But I wonder, what do people use them for these days? I have thought about building one, putting LEDs on all the data, register and address lines, mounting it in a frame and hanging it on the wall as art.. Having it run a clock program or something.. But besides that what are people using these for? I see so many design and construction videos.. but not many that actual show what they are used for.
Very cool. When I started with digital electronics, I made my own Z80 board with hand-soldered wires. I had the CPU, ROM, RAM, PIO, and Serial on a single board. I have always wanted to make a modular card slot version, just as you've done, but I never did more than in-head design brainstorming. Being able to turn ideas into reality is an important skill. Well done!
thank you for your kind compliment. I think after a year or so of using this machine that its reliability over time, especially in my humid climate where oxidization occurs readily, is at stake given so many hand wired signals. I have to spray deoxit often to get it back to life lol. Your singleboard solution is probably best especially if one leverages such services these days PCBWay, but certainly i continue to enjoy the learning tool that this machine has become. Thanks for watching!
Back in the 1980's and 1990's there was a paging (as in pagers) terminal called the BBL for Bill, Bob and Lloyd. It was a Z80 based system, and used distributed processor architecture with a master Z80 and multiple shelves down the chassis with MODBUS's and PIO's that interfaced with more Z80's on each shelf that handled the various tasks, like answering trunks (phone lines), managing subscriber records, encoding the digital paging signals, operating the floppy disc, and diagnostics to name a few. They are defunct now, but I wish I had the manuals so I could send them to you because it was such a beautifully crafted and functional machine, and I just know you would have appreciated it as much as us old paging tech's did, because it rarely ever broke down.
Thank you so much for informing me of such a system. Indeed I respect that architecture. At this point I'm almost tempted to make a parallel processor super computer based on n-amount of Z80s lol! I may just as time goes on. Cray Z80 anyone?
Awesome build! So far in learning in only three years, 555 to home brew computer - wow.
thank you! i really burned a lot of midnight oil 😅
Coward.
This is awesome. It's really cool to see people build new designs with old hardware, and is really helpful for learning computer basics.
you have given my 12yr old soo much ideas!
I hadn’t touched electronics since I was a kid in the late 70’s and early 80’s but jumped back in about a year ago. I’m just starting Ben Eater’s clock module now, maybe I’ll be done with the whole thing in a few years, who knows but watching yours has given me some inspiration. This whole thing has REALLY re-opened my eyes to how gargantuan an effort it was for people like my dad to design and build a working 8-bit computer in the mid to late 70’s, not to mention go to manufacturing with it.
Good work.
Thanks so much for watching Darren. Yes, I was actually so enamored at the concept of a ground-up homebrew exactly from those tales of the 70s. I've seen some really cool unearthings at estate sales and such of wildly unique systems in cool wooden cases and I thought this merging of at-home quality tinkering meshed with the sophistication of production-grade ICs was a unique time in history I sought to emulate.
I just love those transitional moments in tech- like the idea of the horseless carriage, for example. Instead of accepting "the automobile" we saw it as a carriage that required no horse and many "homebrew" ideas burgeoned at that time. This era of computing was equally as tangible to a guy with a dream and a few hand tools. Maybe I'll stick a motor on a milk crate soon and have my own circa 1899 buggy lol. I do seek to build a car like that one day. Good luck on your own build! As I said in the video I went from a 555 timer to a fully fledged micro in 3 years. It's not a fast process... but it's so rewarding to watch it blink on.
You have come a long way in a short time. Very impressive! I hope you are successful in your ventures away from the Z80 project, but also look forward to your return.
Nice job. My first computer was the Altair 8800. This reminds me of those exciting times and all the hand soldering to build a working computer. I hope your adventure away from your lab adds to your future work in ways unknown now.
@Bill When did you get your Altair 8800? I helped a friend build one in 1976 when I was in college. Fun times.
It also reminded me of an Altair.
Really digging the Andersonian approach to presenting your work. Very cool!
Hey cool! I built something VERY similar for my capstone project in college! So cool to see someone else building something like this, keep up the good work!
Man! This is so awesome! Your project is beautiful, the development process, builds, versions, the video documentation! Thank you very much sharing with the world. S2
Years ago when I was finishing the college I gave up on doing a Z80 because it was too difficult for me as a mere junior software developer (At least, it was what I thought at the time). Projects like this tell me to try once more, also because I have a bunch of Z80s, RAMs and ROMs laying on my shelf alongside to other electronic parts and I already work with embedded tech.
love the Wes Anderson vibe on the video
Wow, this is incredible.
Excellent work Joshua, I will be watching your channel.
thank you for watching! i have some cool videos ahead.
Very nice. I've been working on a Z80 system. I've been wire wrapping my build.
Amazing build, It's really stunning how fast you learned! And good luck with the move, I hope you'll be able to proceed with your studies.
thank you so much for your kind words
Great video production on this cool project! Good job man!
Freaking banging bro looks like it was so fun to get accomplished. I appreciate work like this alot great job finding them boards to work on too that was like the most perfect thing you can make in a way, it being modular is the attraction of this alot I think. .. since modular u might want to make swap boards for different operations.
I know some hexadecimal wouldn't take me long to get the hex back just haven't done in a while. Great finish A+
This is reminiscent of the S100 Bus based machines (Cromenco and Comart were the ones I was most involved with) which (usually) ran CPM. At the same time the Shelton Signet used separate modules connected by ribbon cables, a much cheaper method than using a backplane.
Other machines, such as the Superbrain and Televideo used a single board design, Superbrain had the computer, keyboard and monitor in the same case these were at the low end of the market.
Simply inspirational. As a project showcase for the learning path alone you've done great work.
Man thanks so much for the encouragement. My wife is always saying "YOU GOTTA DOCUMENT" and it's true. I just try to keep a good work flow from project bench to Adobe Premiere bench and back again lol. Thanks for watching!
@@joshuacolemanmakes7518 she's right. I've recently started documenting everything and it's so helpful. Obsidian Md has changed my way of working. Hopefully you can leverage this experience into a bank earning career. You've shown what you can do alone. I can't imagine if you had the latest tools and a team with loads of experience to mentor and coach you... Sky is the limit man. Literally.
@@rossmurphy4593 god bless for saying that lol. i am in the midst of a job search now and i marvel at all the old boomer stories of "yeah so i showed up with my pencil case and asked that guy working on the radio what he does and the next thing I know I'm lead project engineer at HP!" hahaha, all jokes aside its rough out here and i dont really know where to start of turning this into a job given that i dont have a computer science degree. 🤷♂ I do however seek to work peripheral to hardware engineers. Wish me luck!
@@joshuacolemanmakes7518 Nice build and documentation! Looking forward to seeing CP/M running, but that's down the road. I had Z80 based micro computers in my early computing days. Thanks for the stroll down "Memory Lane"! Keep up the great work! Kind regards from Calgary Alberta Canada
@@jimf99 it is down the road! I am working on my CF card storage card today actually. all in due time! thanks for watching Jim.
This reminds me of the Sega G80 cage system ...Z80 cpu card, rom card , sound card , speech synthesis card, raster graphics card or vector graphics card . Some great games on that system.
awesome work.
Beautiful music, interesting idea, classic PC.
Greetings from Russia.
Super cool project! Turned out very well, impressed! By the way: some old slot computers had the address decode logic on the main board, making the slots addressable. That way the cards were able to be much simpler, as selecting their address just meant putting it into another slot. You can implement that with a CPLD or sometimes even just a ROM!.
Its six of one or half a dozen of another.
One disadvantage of fixed card addresses is size of page or block access. one size does not fit all. It was more used for channel commands to cards.
On card address decoding is more flexible, it was the choice of ISA bus systtems, by evolution of the many card systems of the 70s..
I recall the Z80. Cool processor. I find it interesting that it would not have been possible except for the 4 unused 8080 op codes. I wonder how many people at Intel regretted opening up that hole for Zilog?
It is beautiful. If only four decades ago the computer manufacturers went modular! Then all computers could stand tall against time and tide. Exchanging one module is mutch more efficient then building a completely new computer every time something new is invented.
A modular computer could easily be updated for stereo, or colour display or a turbo flux capacitor quantum leap time warp processor. Oh boy, they are fast. As soon as they are invented I must get one.
Combining solderless breadboards with prototyping boards is brilliant. I am making a 8085 computer, so I will probably take that approach for a permanent circuit.
I would have used a toggle switch for the cpu speed setting, but the tried and tested jumper way works just fine.
i felt in love with it
Inspiring Video. Thanks for Sharing
Sounds like an old western. Cool project
If you haven't found him yet I would definitely suggest watching a TH-camr named "Ben Eater". He has made a video card and a 8-bit computer on breadboards 👍
im sorry i dont mean to be rude but he clearly mentions ben eater at 3:53 .
@@teacupanimates Ah, thank you. I probably over looked it while watching the video.
Very nice looking system. I recognize those vertical dip sockets! wish I had bought some when they were still available.
they were an offhand buy for sure. but i was like "WAIT! I can use these with the TIL311 displays!". I feel like someone should pcb design some or something. Idk why they're not more common given the package is the same for 7 segment displays.
@@joshuacolemanmakes7518 Ye that is probably what I will have to do. Most of the vertical sockets out there use slotted holes so only dips fit. The sockets on those adapters use some strange slotted sockets but I'm sure I can make it work with normal ones.
Very well done. Greetings from Karachi, Pakistan.
Great video. Nice to see a Z80 build. 🙂 One suggestion though... next time consider using a Udamonic Scamp instead of the Arduino. It's much easier to use, and you can interactively control I/O from the command line. It's brilliant as a control and diagnostic tool when you're bringing up new hardware. It's the most useful embedded system I own.
Wow thanks for the tip... never heard of this device. Seem perfect!
I'm about to start a 65816 project (initially in 6502 emulation mode), and I will be using a Artix 7 CMOD 35T for by clock circuit initially and later my VGA and audio device. I also plan to reuse a BBC Micro B keyboard as my input system (also the FPGA will convert those signals too). So real CPU, real ROM/RAM and I/O chips with an modern FPGA acting as a ULA of sorts.
Love the music!
i love the Wes Anderson-y visuals/editing. Please tell me this was on purpose. great video - I am actually doing research for a script I'm writing. this was helpful.
imma just be real and say yeah film is my passion. intentional it was.
Anderson has an amazing eye for symmetry and his method of referencing an ideal vintage is so well curated. i used the style here because i also idealize that old low-budget-PBS feel that he elicits. there's a real intimacy in the appeal. i was intimate with this machine so i felt the style of presentation suiting.
i also have no budget.
I made one of these 40 years ago. But I used a euro-connector (64/96 way) bus. Why? Because you can use ribbon cable as a bus on part of the connector, and ribbon tails from the other part going to peripheral connectors. Simple, reliable, and non tedious. You also have a wider choice of boards, as the 64 way connector fits any 0.1" board.
For board building I also favour the 'pin wrap' method. No tracks, just a hole matrix, wire goes through an adjacent hole, wrapped around the pin, and then soldered. Gives very high density and reliable, but can be modified. But route well orthogonally and then lace.
That is so cool !
Good job. 👍
Здорово! Мне тоже было интересно изучать архитектуру 4004 процессора, это очень интересно. Далее изучу Z80 )). Сейчас изучаю FFD дисковую систему, как обрабатывать, записывать и читать сигналы с магнитного диска. Это очень интересно! Спасибо за видео и удивительную атмосферу!
Love the modular design! As for the video card, a common choice is the TMS9918, check the LM80C project by Leonardo Miliani. Another option would be having 80 columns and port CP/M to it.
yes! that is the chip i have on hand and i am currently developing the card based on that LM80C project. CP/M would be wonderful. Concurrently, I'm wrapping up my CF card storage device!
@@joshuacolemanmakes7518 If you want CP/M, it's easy enough. Biggest change to your hardware would be having to map RAM from address 0000h upwards. Easy enough to do with a flip flop that's reset during a reset. While the flip flop is reset, ROM is mapped to the low addresses, when set (via an I/O), then RAM is mapped to the entire 64K. And finding copies of CP/M is rather easy, just make a BIOS to fit your hardware, and the BDOS falls in place. Plus, given the amount of RAM you have, if you implement a reasonable way to map it, then MP/M becomes a good possibility as well.
For easy video, just hook up a TMS9118 VDP of your choice with its supporting RAM to your SN76489 PCB.
Great music! ... I'm still watching ... Just wanted to say.
Thanks for the video I enjoyed it.
So sorry to hear you will be away without your lab. Prison won't allow the hot pointy bits???/sarc
Some non-maskable interrupts are like that.
I am an admirer of complex point to point craftsmanship. Few choose such endeavors nowadays with 'progress' modularizing us into blandness. The ironic beauty of your system is that it is "custom modular" with exceptions.
Well Done! :-)
It’s not all sad as I’ll find a way to tinker still. Thanks so much for watching and your compliments.
Nice👌😎👍 ❗
I suppose the values of data and address are displayed hexadecimal, what IC is used to translate binary to seven segment❓
These displays have internal logic to them that does the translation from 4 bits of Binary to it's Hex value. They are called the TIL311 from Texas Instruments. They're a vintage 70s part and pretty useful for these kind's of computers I think. Thanks for watching!
You have made your own Hal 2001 computer ...... (oh yes !! how many of us started off with the good old NE555 timer)
it just seemed the most natural thing to try and understand. then it snowballed as you can see!
and you better believe i'm developing a DAC based around the MC1408 (true vintage DAC) to do a little speech synthesis!
How helpful was Ben Eaters 6502 breadboard computer to you in designing this Z80 CPU? Fantastic work by the way!
Well, I did binge the entire series well before starting this project and I suppose he was a good deal of the animus behind this design. I used the Z80 instead, however, because I felt I understood the assembly routines a bit more and there seemed to be far more documentation out there in the history of documents to aid the homebrew Z80 computer. In all, Ben Eater was certainly a macro guide for this micro. But, I ended up with something all my own in the end. He is a true wizard and an amazing teacher. I couldn't have understood things more plainly without him.
Ben Eater, unfortunatelly, takes little care of circuit details, and sometimes makes faulty designs.
And the idea of whole computer on breadboards without proper chassis is generally impractical.
Hi Joshua, What a nice video! And my compliments for learning SO FAST!
(I've been messing around with electronics since I was 13 years old, but I still don't understand A LOT! )
it's a hobby so you( I ) don't have to!
I personally find Radio and Transmitters the funniest. (I started as a pirate!)
now lisencie Amateur ( Arduino I like it a lot too! ... CNC, 3D Printer... )
Healthy and Friendly Greetings from the Netherlands!
Rob
Man, thanks for that compliment. I have always felt like I see the world in the ways these things work but i just needed to apply that intuition to real hardware. This project was effectively "backtracking" or getting me up to speed on a homebrew computer revolution I missed out on given my birth year.
And as for radio and transmission, when I return to my lab that is exactly the kind of wizard's work I want to get into next. It is such an amazing, nearly completely unique field of study even though some things do cross over into the land of logic and computation.
Best on your own learning endeavors! Maybe when i get my HAM station operable we can talk across the seas!
Why did you need to communicate wit hthe sound IC using the 8255 instead of the bus, like you did with the LCD?
this whole computer was an exercise. i just wanted to see if i could do things sometimes. I wasn't ever choosing the most convenient route. thanks for watching!
Think about the possibilities of the m1 line on the CPU maybe 128 kilobytes of memory
Maybe it's because I just watched The French Dispatch but I really loved the background music
lol!! clearly it is a divisive style given the comments but as I, too, am a Wes Anderson fanboy I'll probably stick to such musical stylings for the future haha. Thanks for watching.
Nice work! Just watched your synth video as well, I remember those interfaces from way back for controlling home robot kits from 8 bit computers. Good to see one of my envelopes in the wild as well. You able to make use of it?
thanks! and wow yeah i wanted to build a robot arm next for my apple II haha.
Forgive me but which envelope are you identifying as yours? Sorry but i grabbed schematics from all over the web and failed to acknowledge where they all came from ...
@@joshuacolemanmakes7518 oh the one on the laptop screen in the titles. I was just pleased to see someone had found it!
@@synthnerd4539 wow dude! what a good eye. but I'm sure since it's your baby that makes sense.
Yes! It is the simplest and only envelope I have on the synth at present. I just wanted something that I could build fast with available parts and your design fit the bill. Really cool you found me here hah! Thanks for your contributions to the DIY synth community.
have you looked at the eurocard standard, I think this project would fit nicely in such a enclosure.
example th-cam.com/video/D28uSzCs7-k/w-d-xo.html
oh very nice! thanks for this lede.
Interesting design and build.. Had a thought about the way you interfaced with the sound card.. why not have 2 busses, the first being the bus you have made already so far, and a second bus, using the same card and edge connectors but connected to the output of the 8255 chip/card...
The idea would be to have the 8255 chard to be the last one plugged in to the original bus, next to that another card with the 8255 output wired to the bus lines. you could use the upper nibble of the third io port to address 16 "low speed io" cards with the other 20 bit for data and other control signals.. add an interrupt line between busses and this would work well for input devices like keyboards that do not need high data rates..
Ohhhhhh I like that! Very clever. Tbh I’m wrapping up on this prototype but I think Mach 2 may just use your idea. Thanks!
Z80 already has a dedicated I/O strobe line, ports are not in ther normal 64K memory address spsce. it's in addition.
With the concurrent DMA transfer commands and internal hsrdware, the Z80 was the premier 8bit CPU,
The Hitachi HD64180 was the icing on the cake, the mega Z80. 8bit.
Are those TIL311 displays? I have a tube of those in storage somewhere.
Indeed they are! Lovely things.
hey exactly how many of these are in your "tub" and are you willing to sell some? i know this comment is coming in late lolol
@@joshuacolemanmakes7518 Tube, not tub. I'll have to find them. I'm thinking around 10 to 20.
I'd probably be willing to part ways with a few. Need some spares, or expanding the number of digits on your computer?
Of course, once I dig them out, I will have to see whether Fran Blanche wants a couple.
Now that you are getting familiar with PCBWay, redesign your computer with modular PCB boards. Might I suggest you check out "James Sharman" here on TH-cam. While he is certainly more advanced in designing the CPU itself, his methods can give you ideas on how to interconnect PC boards to make them modular. You have created a great prototype. Now make the PCB version with the same modularity.
thanks for the recommendation! I'm always seeking people to learn from. Yes, unfortunately, as I mention at the end of the video I am moving and cannot take my lab with me. BUT this is perfect timing to dive into things like Logisim and Eagle more deeply to prepare for my return to Coleman Lab 2.0. Thanks Richard!
@@joshuacolemanmakes7518 why can't you at least bring some bits along with?
@@jonathan_herr voltage is 240, i can manage that well enough w the power supply I have but it's just not feasible for the rest of my bench. this is a move across the world i'm making.
Makers need to film their vintage-processor computer build videos in super-8 if they really want to do it right.
lol! i definitely am amassing the parts for a little super8 studio but i'm aways off as of now. hell a premiere video takes me 6 hours. I imagine a super8 production would take 6 weeks ha!
i'd buy your book on this!
Wow !
Great job(1), it would be more interesting, to create a drive that(store's) 1024mb with added error_correct(feature). Though it would take a long long long long, long time to create such a "marvel" of engineering.
You should pursue your goals. Sorry to hear that your project area/lab does not travel with you.
Well done....might just go fire up my Sinclair
@7:02 The board has a 3.57MHz Crystal and not 4MHz as you said.
Very true! However i have found it the accepted vernacular to round up clock speeds to the nearest value. At very least this was common practice in the era in which this computer would’ve been built lolol. For example, the Apple II ran at 1.023 MHz but it’s called 1Mhz.
I actually rounded in reference to the data sheet of the sound chip which indicates it should be ran at 4Mhz. 3.57 was close enough in my scripting of the narrative and in practically this will just result in a C note, for example, sounding slightly lower.
I may actually go now and buy a 4Mhz on the nose crystal and see how the sound differs. Thanks for watching!
This is pretty cool, and I've always loved the z80. I do wonder though, why did you pay 40$ for a serial program? There are dozens of free and open source serial programs.
None, like minicom, hyperterminal, nor putty nor zterm are as fully functional nor compatible with my FTDI cable and my Mac as this program. I went through the lot of them and they all had varying quirks. For example the inability to send a raw binary file was oddly missing or at least not as easy as this fully featured program.
Plus I’m rich. (🙃jk)
@@joshuacolemanmakes7518 Those are indeed odd quirks, and these sound like some good suggestions for modifying the existing programs should I need them. Which open source tool did you find to be the most complete?
@@anon_y_mousse definitely minicom was the best imho.
@@joshuacolemanmakes7518 Thank you. I'll see if it can be improved.
Well, if you go on eBay and get an old VT220, you are already there: a standalone machine with a display and a keyboard. a VT220 is kinda era appropriate.
And now...a TV typewriter.
cant find the edge PCB prototype boards. 😑😒
you gotta get them fabricated yourself. the link which has the necessary files in on the page in linked in the comments. but here is a link to the gerber files directly
wrcooke.net/classiccomputer/vicproto/VICProto_fixed.zip
@@joshuacolemanmakes7518 ty ill try it
3:17 "80x100cm boards" That's a BIG board. I think actual measurements are closer to 80x100mm. ;) I have registered eagle over10 years ago and it's the first paid version allowing 100x160mm boards and 4 - layers. I'd say it's been enough with 99.9% of my projects.
ha! you're right. :( curse this infernal imperial system! I have been indoctrinated!
I literally mess up the prefixes all the time lol. I'll note in the description this correction thanks for being an astute watcher!
For a moment, I thought you were my brother.
You need to take a look at the TEC-1G if you think a SBC can’t be upgrades or have connection options. 😂
Time to study stuff because I am doing science so please do not ask otherwise I just would have sat there like something else
Red wire goes faster!
very good and interesting, but switch the music please!!
Haha thanks man. Not a fan of George Enescu? Or you’d prefer something more upbeat? Thanks for watching!
@@joshuacolemanmakes7518 I love music, but in this case I would prefer follow your comments
@@VasaMusic438 thanks for the feedback! always seeking to make the channel better.
@@joshuacolemanmakes7518 Your videos are fantastic !! I am studying ( still ) z80 , but being a musician as well I cannot concentrate in your lesson and I follow that good music ;-)
@@joshuacolemanmakes7518 Nice video and wonderful modular design! My understanding is that the music you are playing is the second movement of Ravel String Quartet in F Major, which I love, so my brain was switching between the music and your explanation. Have you considered using the "Standard bus"? It was created in the years the Z80 was king, and suits is well for a modular design like yours.
why?
nuclear calculations and arms trajectory contracts with the United States Government of course
I dont trust those kind of wires in the long term
SBC is inevitable no worries! This is a prototype no doubt. I'll be applying this design to one soon over the many months to come. That, or i'll be designing modular cards that are all properly PCB'd. Thanks for watching!