Here’s an entry in the Open 7400 Logic competition: Lazarus-64
I like the idea of a 74x logic competition! Here is my entry, a retro computer that generates all video using ONLY 74hc logic parts…
The latest version even has a 4 voice sound system, including a white noise channel made using a linear shift register.
Currently, the 74HC chip count is well over 100 and I am still reworking the design.
This has to be the 1st prize. I can’t imagine something more complex being posted in this contest.
Simply amazing.
Well, I was amazed too. Untill I figured out how many ATMEGA micro’s are used there.
That’s just a little not fair to not mention that in description.
What you see on screenshot was not generated by 7400 only.
Oh, too bad. But the early designs were pretty nice too (and only used 7400).
They looked really complex and I thought (maybe it’s just because I’m new to Electronics) seemed more than good enough for this contest.
@Ryn even the earliest designs had AVR.
Oh sorry, I’ve skimmed it and didn’t see the AVR324p ^^ Still not bad tough ^^
I want to try something similar after my current project, direct VGA output from a microcontroller (or many, interfacing a few ATTINY45?), maybe even rendering sprites/graphics.
Hey thanks for choosing my Lazarus-64 project!
The entire video subsystem as well as the sound generator is 100% 7400 logic parts. The AVR is acting like a “cartridge”, hurling out bytes to the dual NTSC video frame buffers, which are made up of mainly 7400 logic and some 32k SRAMS. Lazarus-64 works with any microcontroller, and is all old-school logic at its core.
Cheers,
Brad
Thanks for the positive feedback.
I have not had much time to update Lazarus to the current status, but the AVR sync generator has been removed and replaced by mainly 7400 logic and a bunch of 688 comparators. The sound system is also mainly 7400 logic and counters.
I hope to find the time to update the site soon.
Thanks to DangerousProto for the great site and running this contest. So many amazing projects here.
Cheers,
Brad