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Comment by RicoElectrico | Hacker News Reader

> 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 quite unwieldy (and how did the poor PC rotate raster graphics?)

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I don't think so... I think heads up for the digitizing indicates that the digital map was overlayed on top of the (scanned) source image? As opposed to digitizing from a paper map where you have the map on a surface in front of you, and a digital map hopefully on a screen in front of you (but they did say some were digitizing blind before this?) and you're trying to get the digitized version right by looking between the two.

For the in car map, a vector CRT and vector data makes rotation reasonable. Much less hard than rotating rasterized scanned images on a PC with no rotation acceleration.

I’m guessing the 'blind' method looked something like using one of the early graphics tablets to trace routes or tap control points on a paper map according to a sequence displayed on a text terminal, with no graphical feedback to confirm the vector data during input.

in 1988 i was doing an internship at a company designing ship propulsion systems. they had a CAD computer with with a huge screen and tablet. not sure how old that device was or how expensive but i guess in '85 the technology was not far away.

digitizing blind at that point would mostly be used because it was cheaper than getting a graphics capable computer.

using a projector instead of a screen would be enough to devise a system where the digital image is shown on top of a printed map. so when they came up with that idea they probably already had most of the pieces they need to make it work.

Yes, the map rotated in real time with the vehicle centered. I was a software developer writing software using Etak in '88-'89 time frame. That only worked when focused on a single vehicle, as I remember writing the code to do the same for groups of vehicles and Etak wanted to purchase that code from my employer. they probably got it, as my lead developer I worked for ended up working at Etak after I left.

Interesting side-fact: we used time-of-flight with beepers placed in the cars and ordinary trigonometry to increase accuracy. Worked like a charm.

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).

Rotating raster graphics is easy and the technique was well known at the time, see for example https://www.ocf.berkeley.edu/~fricke/projects/israel/paeth/r... . A PC was easily capable of it. Maybe not in real time as we're used to today, but quick enough that it wouldn't be an impediment.

Heads up map digitizing seem to refer to the method where computer operator digitized an aerial image map by manually tagging its features displayed on the screen, in contrast to heads down digitizing where they used a special tablet.

Anyway I really need such articles from time to time not to lose my faith in humanity.

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