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Remember that the 6502 and its related chipset was not designed to compete with the 8080 or 6800 for general computer applications, but rather with the Intel 40

Remember that the 6502 and its related chipset was not designed to compete with the 8080 or 6800 for general computer applications, but rather with the Intel 4004 for cheap, low-parts-count embedded applications! Keeping that in mind, a lot of the 6502 design decisions make a lot more sense. That folks turned out complex, feature-complete operating systems several times on 6502 is as impressive as those things being done on e.g. the DEC PDP-8, IMO. Doubly so when you consider that the 6502 hackers were often just that, hackers and hobbyists without an industrial-grade budget.

dboreham 3y ago
This isn't true. The 4004 was obsolete by the time the 6502 was designed and nobody really thought of the 4004 as a CPU -- it rose to prominence years later as part of the victors (Intel) getting to write history. The 6502 was explicitly designed to compete with the 6800, so much so that it was pin compatible until legal action resulted in it being changed.
- systems_glitch 3y ago
  I'm trying to dig up the Chuck Peddle interview where he talks about targeting the embedded 4004 and friends market, I'll post it when I finally find it. The interview mentions achieving functional parity with the MCS-4 chip family as the reason for e.g. the 6530 RRIOT. The 4004 was old by then, but not obsolete. It and the 4040 were still being integrated into embedded systems where cost was a major factor through the late 70s.
- systems_glitch 3y ago
  Found it! Bill Mensch, not Chuck Peddle, and it's an IEEE Spectrum interview: https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-processor https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-pr...
kens 3y ago
Interestingly, the 8080 and 6800 were also designed more for embedded applications than for general-purpose computing. As late as 1981, Intel was focused on the various products that microprocessors could be designed into, such as clothes dryers and sprinkler systems. It's hard to imagine from the modern perspective, but the selection of the 8088 for the IBM PC was just another application. Intel viewed the iAPX 432 as their processor for real computing. Take a look at the cover of Intel's 1981 annual report which lists some of the 10,000 products that used microprocessors, putting personal computers down on the list between cameras and solar energy system control: https://www.intel.com/content/dam/doc/report/history-1981-annual-report.pdf https://www.intel.com/content/dam/doc/report/history-1981-an...
systems_glitch 3y ago
SOURCE: https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-processor https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-pr... Bill Mensch tells IEEE Spectrum directly that the 6502 was designed to compete with the Intel 4040, and specifically says not the 8080 or 6800. I don't know how much more "primary" a reference can get, folks.

dboreham 3y ago

This isn't true. The 4004 was obsolete by the time the 6502 was designed and nobody really thought of the 4004 as a CPU -- it rose to prominence years later as part of the victors (Intel) getting to write history. The 6502 was explicitly designed to compete with the 6800, so much so that it was pin compatible until legal action resulted in it being changed.

systems_glitch 3y ago
I'm trying to dig up the Chuck Peddle interview where he talks about targeting the embedded 4004 and friends market, I'll post it when I finally find it. The interview mentions achieving functional parity with the MCS-4 chip family as the reason for e.g. the 6530 RRIOT. The 4004 was old by then, but not obsolete. It and the 4040 were still being integrated into embedded systems where cost was a major factor through the late 70s.
systems_glitch 3y ago
Found it! Bill Mensch, not Chuck Peddle, and it's an IEEE Spectrum interview: https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-processor https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-pr...

kens 3y ago

Interestingly, the 8080 and 6800 were also designed more for embedded applications than for general-purpose computing. As late as 1981, Intel was focused on the various products that microprocessors could be designed into, such as clothes dryers and sprinkler systems. It's hard to imagine from the modern perspective, but the selection of the 8088 for the IBM PC was just another application. Intel viewed the iAPX 432 as their processor for real computing. Take a look at the cover of Intel's 1981 annual report which lists some of the 10,000 products that used microprocessors, putting personal computers down on the list between cameras and solar energy system control: https://www.intel.com/content/dam/doc/report/history-1981-annual-report.pdf https://www.intel.com/content/dam/doc/report/history-1981-an...

systems_glitch 3y ago

SOURCE: https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-processor https://spectrum.ieee.org/q-a-with-co-creator-of-the-6502-pr... Bill Mensch tells IEEE Spectrum directly that the 6502 was designed to compete with the Intel 4040, and specifically says not the 8080 or 6800. I don't know how much more "primary" a reference can get, folks.