8 bit register adds, 4 clocks (equivalent to 2 6502 clocks)
16 bit register adds, 11 clocks, with carry, 15 clocks.
The slowest instructions (23 clocks) are obscure instructions like swap register with memory, or indirect indexed addressing. These were limited by the number of memory accesses needed.
I've built hardware and done a lot of assembly level programming on both the Z80 and 6502. There is simply no substantial speed difference between them for the level of technology available in any particular year.
Most Z80 code was written to be compatible with the 8080. As a result, the second register set wasn't used. Floating point math using the second register set for temporary variables made possible a substantial speedup.
If the 6502 and Z80 waveforms for various instructions are examined, it quickly becomes apparent that the Z80 effectively divided its clock by 2 before using it. This is why, for the technology available in any particular year, they had comparable performance but the Z80 used twice as many clock cycles.
The 6502 was a tremendously clever design for making effective use of a small number of transistors. The Z80, striving to be a superset of the 8080, was also a clever and powerful design for its time.
3D printing was the result of a lot of researchers working on a lot of parts, and when the dust settled, none of them could build a really practical printer without paying off all the other patent holders, most of whom were playing dog-in-the-manger with their patents while trying to elbow out the competition.
You see that with a lot of inventions. They may go through several cycles of invention / related invention / non-conbination / wait / patent expiration until enough necessary parts of the technology are patent-expired that the remaining necessary inventions can be assembled in a single company's product and the technology finally deployed.
Thermoacoustics, for instance, just had its second round of patent expiration and is in its third round of innovation. The basic idea is to make a reasonably efficient heat-engine and/or refrigerator (or a machine that combines, for instance, one of each) with no moving parts except a gas. Mechanical power in the form of high-energy sound inside a pipe is extracted from, or used to create, temperature differences.
There are some really nice gadgets coming out of it, built mainly out of plumbing comparable to automotive exhaust systems and tuned manifolds, maybe with some industrial-grade loudspeakers built in, or their miniaturized or micro-minaturized equivalent. (Example: A hunk of pluming with a gas burner, about 12 feet high and maybe eight feet on a side. Oil fields often produce LOTS natural gas in regions, like big deserts, where it's uneconomic to ship it to market. It gets burned off and vented. (CO2 is weaker greenhouse gas than CH4, by a factor of several). Pipe the gas into the plumbing, light the burner, and it burns part of it to get the power to cool and liquify the rest. As a liquid it's economic to ship and sell it. Then you get to use much of the otherwise wasted energy, displacing other fuel supples and reducing overall carbon emssion.
I hope this is the cycle where things hit the market.
Patents don't matter for making a printer for your own use.
They can matter if you build a business on them, like by selling objects built using them.
Especially if they improve make your process cheaper, easier, more convenient, flat-out possible, or produce a better part. (And if there ARE cheaper, etc. ways to do it, why are you using the patented tech anyhow? B-) )
Patents in the US were about increasing innovation by making first mover advantage truump second mover advantage: Giving the little guy with the bright idea time to set up manufacturing, make back his costs, reap some benefits, and get established enough to compete with existing large companies once they expire. Without them, it was thought, the existing big guys with the infrastructure in place could quickly clone the little guy's new invention and out-compete him in the market, but they wouldn't bother until the little guy had proved it was worth the effort. This would suck the incentive out of the little guys, the big guys would have little incentive to improve, and progress would be slow-to-stalled. The short-term inhibition on others deploying the invention was seen as less of an impediment to progress than having most inventions not be deployed, or even made, at all.
The idea was to set the time limit to maximize progress to the benefit of all/the country, and make manufacturing and technology grow like yeast (ala silicon valley B-) ). Part of the intent was to bias it toward innovators and make established processes free to use, because when the country was getting started the established players were owned by foreign interests. The founders wanted the country to develop its own industry, rather than being dependent on, and sending most of the profit to, big businesses in Europe.
But the time was set for heavy manufacturing at the pace of the period. It's a horrible mismatch for, say, software: With the availability of general purpose computing platforms, able to make distributable copies at electronic speed and copyright to prevent verbatim cloning, a person or company with a new software product can go from steath-mode program development to market establishment, profitibility, and even market dominance in a matter of months, before competitors can engineer their own version. So patents aren't necessary to promote innovation, leaving just their retarding effect holding down the blaze of creativity. (Then there's open source, with its alternitive monitization and/or reward strategies. But that's a "new invention". B-) )
It seems to me that:
- The expiration of patents on stereolithography did help produce the initial explosion of new, and often inexpensive, devices and the improvements in what can be made, how accurately, and how inespensively.
- The availability of machines suitable for practical industrial prototyping - even before the cheap machine explosion - pretty much forced the high-end CAD software producers to include some form of stereolithography output format, while an open output format made the choice obvious. That's a big benefit to the toolmaker for a small effort. The availability in the high-grade commercial tools is a great synergy and helps a lot. But the hobby machines needed CAD tools and open source was already up to the task: Had the big players not gone along it still would have been done, and those big players not "with the program" would be experiencing major competitive pressure from open source tools and competitors that did provide such output.
And here's the key:
- The availabitiy of these rapid general-purpose maufacturing tools will bring (is already bringing!) software's high-speed innovation and entrepenurial models to the manufacture of physical objects. Patents could be shortened in term or reduced to "design patents" - the manufacturing equivalent of copyright - and produce a physical-product explosion comparable to the computer revolution. (Or patents, like "content" copyright, could become the tool of obsoleted established players in the suppression of the competing business models.)
Brace yourself for either the physical-manufacture ramp-up to science-fiction's "singularity" or an ongoing RIAA / MPAA / conglomerate - style legal battle.
Although the names would be nice, even if they were put first they would soon be forgotten. I mean no denigration of the girls involved, but for an article like this the primary interest is the technology, followed by the nation and gender of the inventors. Those are the things that will be remembered, the names are just noise for the general reader.
What's more important: the cotton gin or the name Eli Whitney?
"Too many people" based on what standard? Causing what problem -- food shortages?
"Not enough fresh water". Water for direct human consumption is dwarfed by water used for agriculture, also by water used by industry.
These things are interrelated. Trying to configure them as separate problems is foolish and futile.
The explosive population growth in today's world is in Asia (China and India), and in the future it will be Africa, according to the WIRED article you cite. Think, and you'll see that this supports ceoyoyo's assertion. China and India are both working hard to educate their populations (limited by the deep corruption of their political systems.) I see no such hope for most of Africa.
The anomaly here is South America; why is the population not growing there also?