6502.org

Does anyone else get a little zing of excitement whenever they see these four digits?

There's a donut shop near us whose street address is 6502 also. It's impossible to not think of the processor. But funny thing-- it was a valid number before 1975.

Ah, 1975-76. America's bi-centennial. I was 7 and didn't fully comprehend it, but I remember the celebrations with fondness, especially living in Philadelphia at the time. And with my dad being an EE, I was able to experience the birth of the first 6502 SBC's. Those were exciting times.

But what is up with that number on the Lego box?

Before 6502.org came along, and maybe even before the old Delphi forum, Wally Daniels, an inactive member here who works in the Pratt & Whitney turbine-engine plant in Nova Scotia, and I, exchanged hundreds of pages (maybe up to a thousand pages over several years) of emails on 6502 & '816. It was like a forum where he and I were the only members. This was when email was text-only, and I had a 2400bps modem (or was it 1200?) and my online service was Genie, before the internet really existed. He had a pipe dream of making what he called a "Lego computer" to sell, where it was very modular and hobbyists could buy the basic motherboard and then plug other modules into it, depending on their desires and budgets. The idea is still valid today although advances in technology mean that its form would be different.

I see now after some more research, the 6502 number is irrelevant. Interesting 'that 6502 set' of LEGO's has an astronaut in a mobile 4 wheel unit. It is very valid today, but I'll keep my mouth shut for now, we've got nothing to brag about, yet.

Why the cpu-s codes always had to have a 6 or 8(6800, 68000, 8088, 8086, 1802, 6502...), and why a 4 digit code anyway?

For 6800, it seems likely to be a reference to the PDP-8[1], but I'm not aware of a documented reason for the 5 in 6502. Two possibilities spring to mind: the 5 founding engineers (if they wished to exclude the other 2 who were layout people) or perhaps the year 1975.

As for numbers, I imagine they must be independent company culture: 6800, 4004 and 1802 and then following from those. It's not a bad idea to use numbers for products - they take on a meaning of their own - but obviously not all companies do it. I don't know what Motorola previously made before 6800.

Cheers, Ed

[1] See the Bill Mensch interview transcript http://silicongenesis.stanford.edu/tran ... mensch.htm for example[2]. Note that the PDP-11 was possibly more similar to these micros than the PDP-8. I don't believe Mensch's claim that the 6502 was any more based on the 11 than the 6800 was[3]. If anything, it was a reduced[4] rather than an improved micro: it was a good call that the reduction in functionality was a smaller disadvantage than the reduction in price was an advantage. I'm just posted a new thread on this.

[2] "Motorola 6800 is similar to the PDP 8, okay, check it out. That's where the 8 came from. [...] so the people that were working on defining the 6800 were going to ASU in computer science and learning about the PDP 8 as a mini computer trying to emulate its instruction set"

[3] Some 6800/6502/PDP comparisions here - and see also this Usenet discussion

[4] EDN of Oct 27 1988 quotes Chuck Peddle as "[looking] for ways to make the chip cheaper": "I would ask potential customers what they would give up out of the 6800 if I was going to give them a cost-reduced version. It turned out that most everybody had the same set of things they would give up."

Here's another - so close!
The device measures RPM with a four digit display, but unfortunately doesn't seem to go over 4000rpm, so that's another opportunity missed.

Only 4000 rpm? Even the slowest of 6502s has that beat! Hell, EVEN I could make a 6502 go faster than that!

(And I am mostly incompetent, as an "EE"; I did make those Nitinol muscle wires work, though! So proud of my weak little robot hand!)