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I am interested in the etymology of the name for the 6502 CPU. How were those numbers arrived at by the designers? Do they refer to anything specific? Is there some sort of origin story?

I found some explanations for the similarly named 8008 and 8086 CPUs, but couldn't find anything for the 6502.

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The 6502 is simply the second CPU of the 6500 family. 6501 was a 6500 CPU with an external interface (mostly) compatible with Motorola's 6800 CPU. 6503..07 were as well versions with modified external (bus) interfaces - usually less address. 6508 was a microcontroller with embedded RAM and an I/O port to compete against Motorola's new 6802.

Why 6500 was selected as family name can only be speculated on. The common ground for most explanations lies in the fact that it was basically an improved and simplified 6800, made by engineers that did work on the 6800 before. So they tried to find a 'name' sounding similar but different.

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    One (unconfirmed) theory is that the number "6502", being about 300 less than "6800" was intentional since the introductory price of the 6502 was about $300 less than the current 6800 price from Motorola.
    – jwh20
    Commented Feb 12, 2021 at 17:04
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    On a 7 segment display, we can turn an 8 into a 5 by disabling a couple of functional components. :)
    – Kaz
    Commented Feb 12, 2021 at 20:02

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