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A curious phenomenon called 'Etak'

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Re: A curious phenomenon called 'Etak'

#191

Post by knodi123 »

jpm_sd wrote: post #166
knodi123 wrote: post #152

Earlier quoted context omitted.

I couldn't disagree with you more. Patents exist to reward research or invention that results in practicable ideas. Entrepreneurialism is not (and should not be) part of that.

Ideas are cheap. Execution is everything.

So nobody should be an inventor unless they are employees of a corporation that can afford to commercialize everything they make?

What does the patent even do- protect the rights of the most successful company? At what point does it get taken away from the company that couldn't make enough (what's the dollar threshold?) and to which company is it given (or do they all just use it at once, and then the most successful is awarded the patent, and the rest have to pay arbitrary licensing fees to the winner?)?

Re: A curious phenomenon called 'Etak'

#192

Post by wbl »

ThinkBeat wrote: post #169

Somewhat off topic. What do big military submarines use these days to navigate? Do they have nav systems based on topographic data of the sea floor? (I dont know if it is mapped to the degree its possible). Could that be read accurately with only passiv sensors? I think you could read it perfectly with sonar whatever that may have evolved into these days. I guess they could reach depth where they can poke an extraord…

Inertial navigation complemented with occasional GPS fixes.

Re: A curious phenomenon called 'Etak'

#193

Post by webstrand »

wengo314 wrote: post #63

> The cassette tape in an Etak Navigator was read at about 200cm (80″) per second! i struggle to imagine how did the tape handle it.

I found a contemporary source http://archive.informationdisplay.org/Portals/InformationDis...>

> Compact tape drive. which uses 1/4-in. magnetic tape cassettes operating at 80 ips, each containing every street and specific address, for an area about twice that of an ordinary paper street map, as well as overviews of major state and regional roads, and national interstates (installed under the vehicle dashboard or in the glove compartment).

So it seems that, if it's not 80 inches per second, then the confusion dates at least back to 1985!

another source https://rosap.ntl.bts.gov/view/dot/2332/dot_2332_DS1.pdf> also reports:

> TAPE DRIVE

> 5” x 2 3/4” x 3 3/4" 80 ips

Re: A curious phenomenon called 'Etak'

#194

Post by dhosek »

resolutebat wrote: post #183
sneak wrote: post #181

Earlier quoted context omitted.

Instinctive things are things the entire species are born with. Things you pick up via experience (“nurture”) can never be “instinctive”.

Instincts are not limited to natural instincts. > 1. A natural or inherent impulse or behaviour. > 2. An intuitive reaction not based on rational conscious thought.

I’m reminded of something that I heard someone say once in an interview—intuition is just memory in disguise. Certainly, in some areas of my life, my strategy is to learn things and forget them to be able to use them. It doesn’t work in all arenas (mathematics really demands explicit remembering much of the time, but I find programming and writing both work well with forgotten remembering).

Re: A curious phenomenon called 'Etak'

#195

Post by webstrand »

isoprophlex wrote: post #65
wengo314 wrote: post #63

> The cassette tape in an Etak Navigator was read at about 200cm (80″) per second! i struggle to imagine how did the tape handle it.

That must be a typo, has to be. That's, what, 20-80 rotations per second for a regular cassette tape?!

I found it in the official brochure from Etak printed in 1984, it says "80 ips" http://honeynav.com/wp-content/uploads/2016/01/brochure-Worl...>

Re: A curious phenomenon called 'Etak'

#197

Post by SamBam »

Thtjifiti wrote: post #37
SamBam wrote: post #17

The name is perfect. "Etak" refers to a system of navigation used by Micronesian and Polynesian seafarers to navigate from island to island in the vast Pacific Ocean. Much like this device, it operates by "augmented dead reckoning" (as it says in TFA). The etak system of navigation involves navigating by stars and ocean swells to get the heading, but a key issue when navigating by dead reckoning over long distances i…

This sounds very romantic, but they were mostly at drift. Most very using rafts without any form of propulsion. "Navigation" across wast distances was one way road with no return ticket. They had to do it for overpopulation, not for some explorative spirit.

There is plenty of evidence that Pacific Islanders were able to navigate from island to island, for example in the book I cited above. Here's more [1]. What's your evidence for them not being able to?

Honestly, this sounds like some crap spread by people who can't bring themselves to believe that non-Western "primitive people" could have highly developed skills.

1. https://en.wikipedia.org/wiki/Polynesian_navigation

Re: A curious phenomenon called 'Etak'

#199

Post by rasz »

webstrand wrote: post #193
wengo314 wrote: post #63

> The cassette tape in an Etak Navigator was read at about 200cm (80″) per second! i struggle to imagine how did the tape handle it.

I found a contemporary source http://archive.informationdisplay.org/Portals/InformationDis... > > Compact tape drive. which uses 1/4-in. magnetic tape cassettes operating at 80 ips, each containing every street and specific address, for an area about twice that of an ordinary paper street map, as well as overviews of major state and regional roads, and national interstates (installed under the vehicle dashboard or in…

> 1/4-in. magnetic tape

Tape shown in the video demonstration of Etak was ordinary 1/8 Philips 4 x 2 1/2 x 1/2.

>another source https://rosap.ntl.bts.gov/view/dot/2332/dot_2332_DS1.pdf>

Dimensions are for a Tape Drive so that matches Philips cassette. Speed is 40x normal, but reading https://www.theregister.com/Print/2013/08/30/50_years_of_the...

"The actual production of Musicassettes was done on machines running 32 times faster than normal playback. Cassette tape would be reeled over four heads recording what would be both sides at once at 60 IPS. The master tape that was source of the original music had been recorded at 7.5 IPS and this would also run 32 times faster, clocking up a playback speed of 240 IPS for duplication purposes."

"This super-fast tape transport also required the circuitry to follow suit. So instead of the bias frequency being around 80kHz, it was now 2.4MHz; the amplifiers also needed to work over a frequency range of 200kHz to 500kHz."

Commodore 64 with best tape Turbo is able to store slightly above 1MB per cassette. Japan already had floppy drives capable of storing over 1MB in 1983, but it looks like Etak needed more, with this 40 times faster tape drive delivering:

"local map data base stored on a 3.5-MByte tape cassette."

I would love to learn more details about this drive. Modulation used? Number of tracks? Format? Magnetic flux dump of one of the cassettes would be a lovely puzzle to decode.

Re: A curious phenomenon called 'Etak'

#200

Post by jkillick »

RicoElectrico wrote: post #36

> The second key invention was a ‘heading up’, moving map display. This meant that the vehicle remained at the center of the screen and the map moved and turned under the vehicle. What you saw ahead of you in the windshield was what was displayed on the screen. This proved highly intuitive. Later on they talk about "heads up" map digitizing, did this mean the map rotated as the operator digitized the street? Seems qu…

Heads up digitizing means digitizing the road vectors on top of an image. In Etak's case we used 5 bits to display the image and 3 bits to display the vectors on top. Prior to this invention people used a method of tablet digitizing (similar to https://www.wacom.com/en-us/products/pen-tablets) which was much slower and more error prone (and thus less accurate).
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