[HN Gopher] What if the Apple ][ had run on Field-Sequential?
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What if the Apple ][ had run on Field-Sequential?
Author : zdw
Score : 71 points
Date : 2026-03-08 15:05 UTC (7 hours ago)
(HTM) web link (nicole.express)
(TXT) w3m dump (nicole.express)
| dlcarrier wrote:
| Does anyone know why they call it artifact colors? It creates a
| valid colorburst signal, so the colors are exactly as expected.
| It's high-resolution black-and-white imagery that's more of an
| artifact.
| dn3500 wrote:
| It's a specific technique where you deliberately modulate the
| signal so as to interfere with the color subcarrier. This can
| be used to produce colors that are otherwise not available.
|
| https://en.wikipedia.org/wiki/Composite_artifact_colors
| Dwedit wrote:
| Because they're square waves and not proper modulated signals.
| dzdt wrote:
| Guessing not knowledge but I expect it was called that from the
| accidental occurence of color on broadcast TV wben the image
| includes something with black-and-white stripes at the right
| spacing. So the name predates the intentional usage by the
| comphter system.
| rayiner wrote:
| > But we are saving the lives of ~3 million people so who's to
| say what is bad
|
| Korea's GDP per capita in 1950 was similar to that of Bangladesh
| around the same time: https://www.nationmaster.com/country-
| info/stats/Economy/GDP-.... In the alternate timeline where there
| isn't a capitalist south korea, the Korean peninsula has 100
| million+ people living in poverty and squalor, like Bangladesh
| today. The cost of that is tens of millions of lost lives
| resulting from higher infant and child mortality rates.
| nicole_express wrote:
| Interesting that your takeaway is "capitalist South Korea
| doesn't exist" when I also said the 38th parallel held?
|
| Also I guess now we're discussing the Repugnant Conclusion,
| which is a bit out of scope
| CamperBob2 wrote:
| See also the arguments that more Koreans would be alive and
| well today if MacArthur's plans to nuke the Norks had been
| greenlighted by Truman.
| kryptiskt wrote:
| The simplest way to have no Korean war is if Kim Il-Sung
| decides that an invasion is too risky and concentrates on
| internal matters.
| Zak wrote:
| I had a camera with a field-sequential electronic viewfinder.
| Because it relies on persistence of vision to mix RGB colors, it
| could be pretty distracting if I moved my eye quickly, breaking
| the illusion, and I think it would be similarly annoying on a TV
| or computer display.
| CamperBob2 wrote:
| Tektronix built a lot of test equipment based on color-shutter
| CRTs in the 1990s. It was simultaneously nifty and awful. They
| could render rich, well-defined color waveforms, but as soon as
| you moved your eyes, the illusion would break apart into
| rainbow-colored fragments. It was like watching a movie on a
| DLP projector, only much worse.
|
| Meanwhile, HP OEM'ed a bunch of Trinitron monitors from Sony
| and called it a day.
| Animats wrote:
| Right. Field sequential display means heavy flicker. Do not
| want.
| thought_alarm wrote:
| Hypothetical question:
|
| Let's say that back in 1930s when they were assigning frequencies
| for the broadcast television channels, they allocated enough
| extra bandwidth for a future color (chroma) signal, apart from
| the existing monochrome (luma) signal.
|
| If the bandwidth was available, would it have been possible to
| include separate chroma and luma components in the broadcast
| signal without the two interfering with each other, thereby
| producing a much cleaner color image while maintaining backward
| compatibility with the original B&W TV sets?
| badlibrarian wrote:
| You could argue that if extra bandwidth were available it might
| be better allocated elsewhere for improved picture quality. But
| yes. It would've reduced lots of engineering complexity and
| probably would've looked very much like PALplus.
|
| https://en.wikipedia.org/wiki/PALplus
| tlb wrote:
| Isn't that essentially what happened? In the 1930s, the
| channels were allocated at 6 MHz spacing, but only needed about
| 3 MHz of bandwidth for the luma channel. There might have been
| some foresight involved, but the gaps between channels also
| allowed for cheaper, less precise tuners. Then in the 1950s
| they added a 1 MHz chroma signal on a 3.58 MHz upper sideband,
| expanding the channel bandwidth to just under 6 MHz.
| badlibrarian wrote:
| 6 MHz was there from the start. If it wasn't, the CBS field-
| sequential might have won. Both government (FCC) and industry
| (RCA) were pushing for a backward compatible system and there
| was enough bandwidth to pull it off. OP asks what would've
| happened had chroma been given its own separate, non-
| overlapping band. That was not possible while maintaining
| compatibility.
| dzdt wrote:
| I think in this alternate universe the Apple-II analog would be
| the first cheap computer that could run a spreadsheet. That
| really takes a 40 column display. So I think it would have waited
| for the 2mhz 6502 to handle the doubled line frequency.
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