The economics of the semiconductor industry were also in Wozniak’s favor. Chips seldom sold long at their introductory price. Competing devices from the dozen or so major semiconductor manufacturers usually ensured that prices would fall fast and dramatically. In the fall of 1975 the laws of the industry held true and played havoc with the pricing of eight-bit microprocessors. Wozniak first stumbled on the change when he and Baum traipsed to an electronics trade show in San Francisco and spotted a new microprocessor, the MOS Technology 6502, made by a Costa Mesa, California, company. The men at MOS Technology were aiming the 6502 at high-volume markets like copiers, printers, traffic signals, and pinball machines rather than the small computer-hobbist. The 6502 was almost identical to the Motorola 6800 and the MOS Technology salesmen pointedly stated that their company was trying to make a smaller, simpler version of the older chip. The similarities were so blatant that they eventually became the subject of a lawsuit between the two companies but for Wozniak and other hobbyists, legal squabbles were a distant blur. The critical issue was price. The Motorola 6800 cost $175. The MOS Technology cost $25. Wozniak fished a 6502 out of a large glass bowl brimming with microprocessors and immediately modified his plans. He abandoned the 6800 and decided to write a version of the computer language BASIC that would run on the 6502.”

I don't have much, but I can say there's a 6502 with the ROR bug dated week 51, 1975. It sounds as if the ROR bug existed until June 76, in chips of revision C and earlier. Revision D fixes the ROR bug.

Ref:
http://www.weihenstephan.org/~michaste/ ... meline.pdf

MOS did have some working chips they were handing out at WESCON in September 1975, see
https://en.wikipedia.org/wiki/File:MOS_ ... t_1975.jpg

Here's a quote about that...

During our 2006 interview Chuck explained that selling a dramatically less expensive CPU was not as easy as it sounded. A few years earlier there had been a high profile scam involving a company that claimed it could produce mainframe terminals it would lease for just $10 per month. The company had went bankrupt in a cloud of scandal after taking millions of dollars from investors, and blamed the failure on industries inability to produce cheap chips.

In an effort to drum up interest in the chip they ran an advert stating that anyone could not only see, but they could buy the amazing $25 microprocessor at the WestCon (Western Electronics Show and Convention) in 1975. Unfortunately, when MOS arrived at the show they were told that, in an effort the keep the show ‘high brow’, exhibitors were not allowed to sell product at their booths. Chuck quickly rented a nearby hotel room and had is very attractive wife, sit at a table with two glass jars full of newly minted MOS 6501’s. Little did the buyers know that all of the chips in the bottom of those jars were defective. “Image is everything”, Chuck says.

Godbout Electronics was selling 8008 chips for about $50, so I thought I would look deeper into building an 8008 system from scratch. Well, the 8008 is a real strange little chip, and it's even stranger when you don't understand anything. This put me off the 800 series from Intel. About the same time Motorola had announced the 6800. I rushed down to the local distributor and paid $35 for the giant Motorola manuals and also gathered up all the free literature I could. The Motorola manuals were confusing and not very clearly written. They make perfect sense now, but now I'm not a novice. Even though the Motorola manuals were confusing, they were great compared to what Intel had released, which was downright cryptic! Little glimmers of understanding were flashing in my brain.
...
By now it was August and these strange ads had appeared from a company called MOS Technology. They were announcing a new line of microprocessors for $20 and up. $20.00! And, they said you could buy the things at the upcoming Wescon show in September. This was un-heard of. Remember that at this time an 8080 was still $175.00.

What a furor this created. Intel and Motorola seemed to be implying that the $20 price was a phony comeon, like you could only get that price if you ordered a million units. Other people were convinced that it was an out-and-out fraud. One salesman I talked to was convinced of this, and I remember him distinctly telling me that the microprocessor chips had reached their bottom price—$175— and that we'd never see them go any lower. I countered by saying that soon we'd see the price of micro- processors drop to under $10 in the next year or so. He said "Never!"— told me I was crazy and everyone else standing around agreed with the salesman.

The only thing to do was to wait and see what happened at Wescon. Well, along came the day of the show and, sure enough, there was MOS Technology but no chips in sight. I was informed that no selling was allowed on the floor, but that the chips were available in their hospitality suite. Away I went to the hospitality suite to find out the real story.

There they were! A big glass bowl of chips and stacks of manuals. They also had a KIM and a TIM system running. A guy named Chuck Peddle was there, happy to explain the features of his newly born baby. They plied me with a drink and I sat down on one of the couches with a copy of the manual to have a look. The damn thing made sense. Take my money!

I went home that evening with a 6502 chip and a hardware and I still needed more "modules" for my system so I decided to build them. software manual. My own computer and all for $25 dollars. Little did I know that I would invest another $300 before my homebrew 6502 system would work.

It is interesting to note that this very day Intel and Motorola an- nounced price reductions on their processors to $79.00. The microcomputing craze was really beginning. I would like to point out that no one has really credited Chuck Peddle for bringing the microprocessors within reach of all of us.

Mensch: Well, the first wafers that I worked on a Motorola, they were like 2 and 1/2 inch wafers. But I think we probably were three, I don't know if they had three and a half, but I don't think they were four inch wafers. But what Ed Armstrong, the process guy that was the head of process at Motorola for the NMOS process at Motorola, he grew a long beard waiting for 10 good die-per-wafer, and we were getting like 100 good die-per-wafer on the 6502. We had at least 10 times the yield per wafer, and it was because of their “spot knocking”..

Diamond: And what is that, “spot knocking”?

Mensch: Well, when you build a mask, you have flaws sometimes in the material that's used--

Diamond: Now, are these contact masks at this point?

Mensch: Well, no, that's another thing. The contact mask meant that you would wear out your mask after using it a few times, so these were projection-- proximity, so it was proximity if I got it right. And so that means it didn't touch the wafer-- so if you've got a good mask, you had a good mask that you could use for hundreds of wafers as long as you didn't damage it. So the “spot knocking” meant that if you compared two, you're not going to have a hole in the same place on both masks. So then if you went in and put little ink or something to cover the hole up, you could create a perfect mask. That's what we had.

Diamond: So you retouched the masks.

Mensch: Yeah, yeah. Motorola wasn't doing that, so we had the advantages in the manufacturing. So when we sold a $20 6501 and a $25 6502, we were making money.

Diamond: So your team went to MOS to build a microprocessor. Who came up with the architecture of the processor?

Mensch: Well, it would be Chuck, I would say. I'm a semiconductor engineer, so I'm building what Chuck wants built. When I did step in and started defining things is when I realized there were some basic things here that could make a big difference. Motorola 6800 had a clock generator that they sold for $69 on top of a $375 microprocessor, so if you add the two together, you got over $400.

Wozniak fished a 6502 out of a large glass bowl brimming with microprocessors and immediately modified his plans. He abandoned the 6800 and decided to write a version of the computer language BASIC that would run on the 6502.”

At the consumer level, x86 crushed everything else. (Actually, Windows crushed everything else -- there were other OSs on x86 that never really got anywhere, such as BeOS).

Regardless of Windows, x86 is still on top in performance per watt (tons of performance at many watts at the high end; ARM has lower absolute power draw at the low end, but not the perf/watt ratios). I think POWER architecture has chips with greater absolute performance (especially as their caches have been absolutely massive), but cost and wattage are much higher than x86. So yeah, once Intel really got rolling, their chips kept on top, and volume meant consumer affordability.

So yeah, once Intel really got rolling, their chips kept on top, and volume meant consumer affordability.

AMD played two parts here...they effectively killed Itanium as a future 64-bit platform...

Well.. many people claim that the current x86 architecture is simply a VM running on a RISC architecture. I can't really disagree when looking at today's Intel CPUs, they are completely different beasts from yesteryear. Tons of registers etc. The registers exposed to programmers are just what the x86 VM wants you to see.

AMD played two parts here: First, by competing with Intel they got Intel to start working on performance. But secondly, they effectively killed Itanium as a future 64-bit platform, which is a bit of a pity - when it was around it was way faster than the same-generation x86. We had an Itanium server at work. Great system. But that road was effectively blocked when the 'easy' road of amd64 was made available, there wasn't enough traffic on the Itanium road to make it a cheaper, faster option. I for one couldn't care less about 32-bit 'Windows applications' compatibility and would never have looked back if Itanium had gotten enough momentum to get into consumer products. The only potential (and definitely possible) roadblock to that future would be if there weren't any other alternative 64-bit competition, to continue to pressure Intel to improve performance.

Several portions of the 29050 design were used as the basis for the K5 series of x86-compatible processors. The FPU was used unmodified[dubious – discuss], while the rest of the core design was used along with complex microcode to translate x86 instructions to 29k-like code on the fly.

That may be, but at the time, the Itanium was much too expensive to become a mainstream processor. Since then, the x86-64 architecture has gotten so ridiculously fast it doesn't matter any more.