Re:Build an 8-bit CPU from scratch
by MaxBarraclough on Monday December 14, 2020 @06:52PM
(#25425075)
What's the legal situation of the 6502? Would there be risks in making them at scale?
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The 6502 has a patent on decimal addition (#3,991,307), but that's long-expired. MOS Technology got sued by Motorola for making the 6501/6502 because they violated Motorola's patents on the 6800 and took trade secret documents.
IC masks are protected as of 1984 (mask work is essentially copyright for the die), but the 6502 predates that.
Some companies (such as Intel) copyright the assembly-language mnemonics, but that wouldn't be an issue.
I can't think of other issues with the 6502 but I'm not a lawyer. Note the MOnSter 6502, a copy of the 6502 built from discrete transistors. I should also point out Ben Eater's 8-bit CPU is a simple design, not a 6502.
Re:Build an 8-bit CPU from scratch
by userbinator on Monday December 14, 2020 @08:28PM
(#25425925)
IC masks are protected as of 1984 (mask work is essentially copyright for the die), but the 6502 predates that.
...and the copyrights for masks are much shorter than traditional copyright - only 10 years in the US: https://en.wikipedia.org/wiki/Integrated_circuit_layout_desi...
Re:Build an 8-bit CPU from scratch
by colejohnson66 on Monday December 14, 2020 @07:18PM
(#25425303)
Well, Ben Eater isn’t the one making them, but Western Design Center (WDC, no relation to WD) who supposedly owns the rights to produce them. Eater is just reselling them which is allowed under the “first sale doctrine”
Re:Build an 8-bit CPU from scratch
by segfaultbuserr on Monday December 14, 2020 @08:26PM
(#25425908)
> Western Design Center (WDC, no relation to WD) who supposedly owns the rights to produce them.
The founder of WDC, Bill Mensch [0], was one of engineers from the original 6502 team at MOS Technology.
Re:Build an 8-bit CPU from scratch
by colejohnson66 on Tuesday December 15, 2020 @10:03AM
(#25430895)
Well that certainly explains it. I never knew that