68030 @ 16MHz vs. 68000 @ 16Mhz: how much faster?

[Gorgonops]

If HCMOS existed in the mid-70s and there was no price difference, why wouldn't they have used it to begin with?

I didn’t say it existed in the “mid-70’s”, I said it was invented in the late ‘70s and started becoming mainstream by the early 1980s. (Replacing the older, very slow original CMOS process used in the 4000 series parts.) CMOS versions of CPUs originally released in HMOS were pretty readily available by 1983 or so. (8085, 65c02, etc.) The 80286 was the last NMOS new design Intel CPU, the 386 was also HCMOS and that was in prototype in 1985. Considering the portable didn’t come out until *four years after* your 1985 figure what Motorola thought it was worth when it was brand spanking new is kind of irrelevant.

(Motorola also has a long history of price gouging. The whole reason the Apple I was built around a 6502 instead of the 6800 is MOS charged 1/10th as much for it.)

TL;DR, HCMOS was old news by 1989. I have a 1986 Tandy computer sitting on my desk that I’m intimately familiar with the guts of, and it is largely made of HCT, which is HC with special sauce added to make it directly mixable with TTL. If HC was still impossibly expensive in 1986 you could lay everything you own on the bet that Tandy would have bought LS instead.

 

[Gorgonops]

Some brief internet sleuthing suggests the original HMOS 68000 was $487 when introduced in 1979, while the HCMOS 68HC000 version was about $800 at introduction in 1985.

Also of note: inflation was Kray-Kray in the late 1970s and early 1980’s. According to the inflation calculator that spread is only about 15% more than the general inflation rate between those two dates. Not saying Motorola wasn’t kidding themselves with that price, but there is that.

 

[Franklinstein]

I didn't get a ton of semiconductor sales sheets from the 1980s turning up in my 10-minute search, so I don't have accurate figures from launch onward, just a few articles that stated "the 68HC000 will be roughly twice the price of its NMOS counterpart" at introduction in 1985. I'm sure the prices went down with the march of progress and the introduction of successor chips, but even if the difference shrank to only $5 more, it's still a higher cost than the original variant. 

 

[Gorgonops]

Here’s an announcement from 1988 for availability of new 16mhz versions of both the regular and CMOS 68000s.

https://archive.org/details/computer-magazine-1988-05/page/n99/mode/2up/search/68hc000?q=68hc000

and, yep, the CMOS one is about exactly twice as expensive... but the difference is $18 vs. $34, quantity 100. So, yes, it’s “high cost” but by no means of a magnitude that meaningfully affects the price of a $6000 laptop.

As for why it cost any more at all, it’s probably about a 50-50 mix of “because they can” and there being some capacity premium on foundry space for making high-density newer process chips.

... edit: also, don’t forget, the HC000 is a fully static design and therefore actually has more transistors than the NMOS version. So you are actually getting more for your more money.

 

[Gorgonops]

... edit: also, don’t forget, the HC000 is a fully static design and therefore actually has more transistors than the NMOS version. So you are actually getting more for your more money.

Actually, scratch the fully static thing, I double-checked and the original 68HC000 still had a minimum clock speed. It wasn't until the SEC version that you could completely stop the clock on a 68000.