Dajgoro wrote:
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."