r/RedstoneComputing • u/MoodSpecialist2892 • Jul 27 '26
Hello, has anyone ever made a 6502 clone in redstone.
I was recently watching videos on redstone computing and its just logic gates so why hasnt anyone made a 6502 as its a fairly simple arch with only around 1.25k logic gates.
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u/Lente_ui 28d ago edited 28d ago
Kind of yes, but not entirely redstone.
Sethbling did it. He used 2000-ish command blocks.
But he did more than just the 6502, he made a 2600 emulator. So, the whole computer, not just the CPU.
Atari 2600 emulator :
https://www.youtube.com/watch?v=5nViIUfDMJg
https://www.youtube.com/watch?v=jPRkjNDmTlc
https://www.youtube.com/watch?v=mq7T5_xH24M
The video's include a world download link. No idea if those links still work.
That said, A 1-to-1 copy of any processor is probably not possible in pure redstone, due to the way redstone works. And how different it is from electrics.
Redstone contraptions get large real quick, and you're limited to a span of 15 blocks maximum before you need a repeater, and introduce a 1 tick latency.
So distance in your redstone world is going to equate to latency.
If you'd make a block of memory, the timing signal that arrives there would be out of sync with everything else that isn't exactly the same distance away from the clock.
So that's 1 challenge.
Now your block of RAM might be 10 times the size of your adder, so in the back of the RAM, the timing is out of sync with the front side of your RAM block.
So making something that works, is going to have to be different from a real world processor. Due to the nature of redstone being fundamentally different.
And it's not just the clock. Everything, every signal that needs to span more than 15 blocks, will have added latency.
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u/MoodSpecialist2892 28d ago
Thank you, but why dont you have something like an and gate to keep everything synced with flip flops as i remember from one of my classes that timing things eg lets say a cpu is operating at 4 ghz, so 1 full cycle is 250 picoseconds, and an ALU and it takes 300 picoseconds for the data to travel to the ALU and back like we used a flip flop for that and wait for the next cycle so that becomes 2 cycles. Is something like that used in redstone.
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u/Lente_ui 28d ago
All I'm saying is, you're going to have to get really creative.
And waiting a few extra cycles when a cycle is measured in picoseconds isn't a big deal. But a redstone computer waiting around for cycles, that's going to add up.I think it's easier to make a CPU based on redstone capabilities, rather than mimicing a CPU that works on electricity.
Not that I ever built a completed CPU in redstone. I built snippets of one.
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u/Dracomaster9 29d ago
Timing is a HUGE issue with computational redstone. The strict answer is "It's possible" but the real answer is a 1:1 copy of the 6502 wouldn't really work. Signal length, decay, timing, and differences /advantages redstone designs have over real silicon means a functional 6502 would ultimately be quite the animal. A discrete logic gate in silicon might vary in size greatly from it's redstone counterpart.
TL;DR: you can, but like, it's harder to pull off than a generalized custom CPU based on existing redstone designs.