Latest prototype of my 8-bit computer [Zeal 8-bit computer]

Hello, world!

Welcome back to this new video, today Iam going to share the status of the project by presenting you the latest prototype of Zeal 8-bit computer that you may have seen in the previous videos. Several hardware bugs were fixed and new features are here.
You will also discover the new video chip/board, based FPGA, that I am currently working on.

I hope you will enjoy this video, don't hesitate to comment if you have any suggestion or question!

You can find me on the following platforms:

[esra_erimez]

As a software engineer, I'm in awe of this type of project. Hardware has always alluded me

[belatorok]

It is not a coincidence that you have so many views, you are massively talented, I think.

[ravingidiot]

This is fascinating, thank you for sharing your development process! I had considered using 3 4x4 register files in my MMU, but I most of the ones I saw were obsolete. In that design, I ended up going with the 74610 instead, but it's kind of awkward to use because it has a 12 bit data bus, so as far as I can tell, the 4 upper bits would have to be buffered. Given this I might consider looking at the 670. I believe my MMU design differs from yours in that a) I use 4KB pages and b) that I also intend to encode memory protection into the page table. The 670 looks like it has the advantage of having a surface mount implementation, so overall it might still have advantages over the 610. Thank you for the inspiration, and happy hacking!

[Theineluctable_SOME_CANT]

Me again...

Now I have sat down and WATCHED your video:

Nice work, brother!

I am sure you have been on an amazing journey in the design and fab of your glitch free system.

Very nice!

I can see my ravings might have shocked or offended you.

I had a friend who went into television (broadcast) in 1985 or so, when I was fixing ETWs and primitive desktop computers (6802 with BASIC in ROM and tape....) by day and hand coding my 6802 system at home by night, building the furniture one stick at a time. The hardware was a true, delightful Frankenstein of a video arcade game, my custom keyboard and my custom video display. Quite the business! Lol.

[atamairon]

Hello. It's a very interesting project. Congratulations. Z80 is a processor that never will die! I'm a lover of 8-bit system. A lot of us we've growth near of these microcomputers. I wait for new advances in the project. Go it!

[sanhua]

I follow your project for almost one year. I am surprised that you have gone so far and made these improvements! The latest prototype seems really exciting. Could I buy the kit ? ( Z80 motherboard and custom video board)

[mitsuruyamada]

Congratulations on the progress of your homebrew computer development! If the CRT interface were made with standard TTLs, the circuits would be troublesome, but it is realized with FPGA and is very integration. I am making my own computer with an old 8-bit CPU too. It is fun to learn the basics that are lost in the latest PCs.

[horseradishpower]

This is incredible. You have managed to condense the project, and in the process used the freed up space to add more features.

Moreover, this is going to take up a much smaller footprint overall. This adds to some greate possibilities, such as creating a computer with the same sort of footprint as a Raspberry Pi 400. I mention this, because then it would have a retro computer feel, which would be awesome for this wonderful little project.

I also suspect I have missed a few videos, because things seem much further along than when I last watched.

Keep going, this is great. I can see you get to a final version in the next six months or so, easily.

[Theineluctable_SOME_CANT]

Great work!

I am 59.

I was a bit too old to get the bug as only young pre-teens can, but I was into doing 8 bit hardware and software (firmware mainly) as a hobbyist.

One very very advanced CPU was the MC6809E a multiprocessor environment compatible device.

I get that you are a Z80 fan boy, but if you look into the E variant of the MC6089, it will shock you.

Truly unique, Excellent device!

[Jasonsadventures]

I've been following for a while. Because it seems like the best chance of someone with the skills being and to build my dream computer too. All I ever wanted in my life was a 8 bit home computer powerful enough to run at around the sprite and graphics performance of early 80s arcade games. Do you have this working on 15khz video?

[gyorgypaczai]

Really a usable and a modern environment for this old cpu. Great work! The OS is looks also very good, nothing fancy, only useful and important commands. Can you tell us how the memory management unit works in detail if it is not a secret?

[vanhetgoor]

Yeah! Eight Bit! And an FPGA working overtime in 64-bits minimum. In fact every bit is looked after from many viewpoints, every bit is checked from the left and the right, weight, speed and direction is controlled. How would you get all of those bits looking in the same direction if there was not something bigger behind it? All bits are marching exactly on the right time. When Von Neumannn started with computers they often had to wait for slow bits that always came late.

Very nice. Will you be releasing the schematics?

[jaycrutti]

Would you consider making the video card something designed for "stand alone" use with other systems? For example, a version that could be used with 6502, 68000, or other architecture systems. And does the video card support 16:9 aspect ratio and 720p or 1080p resolutions? It could be a real game changer if it could be redesigned as a platform-agnostic, retro-friendly video solution.

[scotts-tech]

How did you attach that bga fpga to the video board? The largest non-bga fpgas they make only come in 144 pin packages. This means that if you can't do bga parts but still need high pin counts, you have to use 2 qfp chips working in tandem which ends up being twice as expensive.

[samuraiBSD]

So, I've been wondering with a lot of these modern retro computers, why not design around modern PC form factors like Mini ITX so that cases and such are simpler affairs? Just curious if there's a reason I'm not seeing.

[e-radfilms]

By chance will you ever make this more modular using something like old 8bit ISA bus connectors? a backplane with power and cards for each section such as cpu, ram, video, and sound?

[lymmentrixprofessional]

Thanks for this wonderful and awesome project, please can you send the schematics diagram and PCB layout

[Theineluctable_SOME_CANT]

Oh, yes.... the MC6809 has an MMU chip available which gives 2 MB address space. Also, OS9

I did have a Spectrum, which I did some simple machine language on. Never was that excited about the register oriented aspect. Okay, but not blown away.

Z80 does have an IO space though, which is good.

Motorola memory mapped their stuff, like the PDP-11 which inspired them.

[gensys]

Any future update on video card status if you will be making it available to be purchased ?