I randomly stumbled across this impressive, home brew graphics subsystem for C64 today. The goal seems to be pushing the boundaries of what would have been possible with period-correct, through-hole 74LS parts (no FPGA or ASIC) toward advanced arcade-level graphics hardware. Quite ambitious for a one-person hobby project and, as the video below shows, very successful!

https://www.youtube.com/watch?v=MLVZav7mVcI&t

is it C64-specific though?

There are numerous mentions to Z80 as well as C64, and the arcade hardware was Z80 and this project started life as a plug-in compatible board, so presumably it still has support for being driven by Z80.

If it started life as a Z80 board, probably the C64 interface is just synthesising _RD, _WR and _MREQ (and maybe _IORQ) that a Z80 design would need from the RD/_WR, clock and high address bits on 6502.

8 data bits, write signal, reset address state logic. Each byte written will prime the 24 bit address to write to in the hardware and then store bytes with auto-incrementing address. This lets the C64, or any other machine capable of generating those signals, to write large amounts of memory to the hardware.

What about ULAs? That's what the ZX spectrum used. They're not quite FPGAs, and not quite ASICs.

jesus dude... thats amazing.

This is impressive af but it seems like so many projects are just people building nostalgia instead of something original.

There is value in going back in time to revisit old hardware. It helps you gain insight into technology today and who knows inspire someone to take a path that was missed back then. This may lead to original ideas.

Build something original then!

This is original :) It includes new functionality like multiple layers, layer priority, multiple palettes, scaled sprites, mode7, dithering, etc

I know, I was replying to the GP, whose definition of "original" this didn't fit (and that's fine, but, instead of complaining about it, they should build things).

Ahh:)

I do all the time. I just don’t feel the need to tell everyone.

Unless they build something that you deem not original?

So you would rather waste time in spreading negativity than positivity? Ok.

Depends on your viewpoint.

It's "just" someone making a graphics card in their free time for the hell of making one. That "just" is doing some heavy lifting.

This question is even covered in the readme.

> Why bother, you're probably asking? Well if you have to ask then perhaps you're not the right audience. :)

Right. And this is a discussion board. And I’m discussing my opinion. Is that not ok by your rules? Last time I checked HN allows dissent. Or maybe you’re just not the right audience for this discussion. ;)

The correlation between old hardware stuff and nostalgia is not always as rigid as people on HN tend to think. a lot of stuff like this is made by people born years after the source media(?) (I don't think this is though)

I have to admit, and it only happened once, i threw a sickie at work (92?) to finish playing bombjack.

Another game I'm looking for is 'prensorium'.

Thank you for posting. This is one of my projects. I was wondering why all the subscribers joined today.

What's the relation between this and MAME? I don't have the Bomb Jack arcade PCB (I've got others though) but I do have a Pi2JAMMA and, well, Bomb Jack using MAME.

Is this project something that could be replacing (partial?) hardware on a real Bomb Jack PCB (not unlike what some are doing with C64 chips, where new replacement can be dropped in place of old broken chips)?

It started off as a direct Bombjack arcade hardware replacement, it then grew way beyond what the arcade was capable of. MAME is software, this is hardware, no relation. :) Although interestingly the first version of the hardware did allow me to find a bug in the MAME implementation.