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Interesting article on history of 6502

Interesting article on history of 6502
by on (#151442)
Thought some people might be interested.

http://archive.archaeology.org/1107/features/mos_technology_6502_computer_chip_cpu.html
Re: Interesting article on history of 6502
by on (#151453)
From the article:
Quote:
But the Nintendo Entertainment System outsold every other device that the 6502 appeared in, combined, moving close to 62 million units.

This means fewer than half of all 6502s shipped have a decimal mode.

Quote:
One Bay Area 6502 fan who saw the simulation obtained the netlist from the Visual 6502 team and fed the description into a “chameleon chip” called a field programmable gate array that consists of many transistors that can be programmed to connect in different ways. By lending the chameleon the characteristics of a 6502, he was able to hook it up to an old Atari 2600 and run games.

Has anyone tried pulling the netlists out of Visual 2A03 and Visual 2C02 and sticking them on an FPGA in this manner to see if they work in an NES?
Re: Interesting article on history of 6502
by on (#151454)
tepples wrote:
Has anyone tried pulling the netlists out of Visual 2A03 and Visual 2C02 and sticking them on an FPGA in this manner to see if they work in an NES?

But the NES CPU is more than just the 6502, you can't simply swap one for the other and expect it to work, can you?

EDIT: Sorry, I didn't see you mentioned the 2A03. I didn't even know/remember there was a Visual 2A03.
Re: Interesting article on history of 6502
by on (#151455)
The Visual 2A03 netlist also contains the APU and DMA controller.
Re: Interesting article on history of 6502
by on (#151458)
tepples wrote:
Has anyone tried pulling the netlists out of Visual 2A03 and Visual 2C02 and sticking them on an FPGA in this manner to see if they work in an NES?

I was wondering the same not long ago, but more from the viewpoint of "why hasn't anybody done that". It wouldn't be a straightforward thing to do though, because Visual 2A03/2C02/6502 is on a lower abstraction level than HDLs. I'm not sure if there'd be a good way to do an automatic translation from the VisualXXX level presentation to HDL, but if not, maybe a manual translation to gate/RTL level HDL would be doable.
Re: Interesting article on history of 6502
by on (#152222)
If we have working models of the 2A03 and 2C02, companies should be able to make accurate clone chips. This would only require the two chips to be cloned plus the six generic logic chips, but they all use NES-on-a-Chips instead. I guess it is too costly to implement a board with true clones these days.
Re: Interesting article on history of 6502
by on (#152231)
The famiclones are already something like 99% accurate.

Running a new mask would cost tens of thousands to millions of dollars, and there's basically no margin in the market available to make a new mask.