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Comment by peatmoss | Hacker News Reader

In a modern world where we backlight semiconductors to produce high dpi screens, it almost feels weird to think we used to fire electron guns towards our eyes. I was always partial to the amber screen.

Has anyone recently played with an old Asteroids cabinet? The screen is a black and white CRT. When you fire a missile, the screen effect is insanely bright. I'd forgotten just how intense that was.

I can't wait until someone pieces together an art piece that makes use of all the crazy analog video effects that we used to take for granted, but now look like alien technology.

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Way back in the 90's my CRT monitor went out. Money was tight so I had to wait a couple of weeks before I could replace it. I went to a local computer repair shop (as in, actual repair, like replacing blown capacitors on mainboards and such) to see what I could get for cheap, as a stopgap. The guy had an old monochrome CRT he had repaired--the kind with green pixels--probably 6-7 years old at the time. He sold it to me for like 8 bucks. I figured I could at least use bitchx and links on it until I could get a new monitor. After a few hours in front of it, I started feeling really itchy, and the screen had enough static charge to raise the hairs on my forearm if I moved near it. Pretty sure it was shooting cancer directly into my face. Good times!

> Pretty sure it was shooting cancer directly into my face.

I always assumed the metallic aftertaste I got after long coding sessions was unrelated.

Asteroids was a vector game, interesting technology:

http://en.wikipedia.org/wiki/Asteroids_%28video_game%29

http://en.wikipedia.org/wiki/Vector_monitor

Better resolution and frames per second than modern games :)

Like a plotter, effectively infinite resolution (not really infinite because of the phosphor elements being finite, but still).

The limitation shifted elsewhere of course, and that's in the complexity of the scene, specifically the number of objects.

Still, interesting tech and can even be adapted to control a laser unit that renders on say a big building or even the clouds (the real ones).

Playing Asteroids on a building would be kind of neat. Has anybody tried that?

Yup. There were some laser enthusiasts that connected their projection systems to MAME and created Laser MAME.

Laser galvo speed is a big factor in making it work effectively but there have been some great demos, like John Knoll (from ILM) playing Atari Star Wars on a theatre screen:

https://www.youtube.com/watch?v=W4REBVgm4Nc

not really infinite because of the phosphor elements being finite

There are other limitations, such as beam deflection imprecision and precision/speed of the A/D converter and the size of the electron beam in relation to it's brightness. Tighten the beam focus to get more precision, but it will be way dimmer and harder for a player to see. Make the beam stronger to compensate and you'll burn a hole in the phosphor. Your costs also go up with the fancier parts and beefier power supply.

The Atari system settled on 1024 points of resolution on each axis (but clipped to 1024x768 for the 4:3 monitors used at the time). Still a lot more resolution than the low-res arcade monitors of the day, which were roughly CGA-class (around 320x240).

Back in '97, I built myself a vector graphics card for a computer which plugged into an oscilloscope for a university project. Good fun. Of course, to persuade the university to let me do it, I described it as a "programmable dual synchronised waveform generator", but it was always intended to display images.

Jed Margolin (ex-Atari) has the definitive history of the Atari vector games and how the hardware works:

http://www.jmargolin.com/xy/xymon.htm

http://www.jmargolin.com/vgens/vgens.htm

Asteroids was a humble 6502 running at 1.5 MHz with a PROM-driven pseudo-CPU acting as the vector generator.

Vector CRTs are all kinds of neat technology. I own a Tempest arcade cabinet, which is a color vector CRT, and it's such a huge difference from using regular raster CRTs.

It is. It was only 2 colors, but it was high resolution, especially compared to other screens at the time. There's one in my Vectrex sitting near my desk.

http://en.wikipedia.org/wiki/Vectrex

Another use of vector graphics is in older aircraft displays, where the writing and lines would be rendered that way, sometimes with raster scanning for the artificial horizon.

I played with an old Asteroids Deluxe machine just last weekend! They have one at Barcade in Manhatten on West 24th.

The vector display sits face up in the bottom of the cabinet, and the game is reflected on a one-way mirror set up in front of a backdrop. Those super-bright vector graphics are even more impressive when they look like they're floating!

It's interesting that xterm still provides an emulation for the old Tektronix vector terminals. I'm not aware of any software currently in use, besides PAW and gnuplot, which is still using Tektronix.

Check out the video art people have been making with old Vectrex game consoles and modular synthesizers. http://www.muffwiggler.com/forum/viewtopic.php?t=69637

> When you fire a missile, the screen effect is insanely bright.

There was a rumour that people who played on a Vectrex (a vector display home console) would experience eye damage after protracted sessions.

Without any reasonable understanding of what amount of light results in eye damage, I find this plausible. My reaction to seeing Asteroids for the first time in many years was to try and draw comparisons to other things. I ruled out welding light as being far too bright, but the comparison did suggest itself.

A bit of anecdata: I spent a lot of hours on a Vectrex and didn't get any eye damage :-)

My memory is a little fuzzy. I remember a game at the St. Louis arcade museum that was b/w vector and very bright when I went there about 20 years ago. It could have been Space Wars, though.

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