VOGONS


First post, by Xfing

User metadata
Rank Newbie
Rank
Newbie

Howdy folks!

In one of the discussions I had today on the Descent discord, the topic came up of my old, monochrome monitor that I used to play Descent on. After about an hour of searching, I was able to zero in on the model number - it's an SM-470.

What's interesting about this monitor (and what I'm after) is its distinct brand of monochrome, which is not equivalent to true grayscale that you can easily get on modern monitors. Here's what it looks like (this image is from some Czech auction site): a2d178f8-08d9-4d45-9ecd-41c604b02cc3

You'll notice that the grayscale is warmer and with a hint of brownish or perhaps greenish here - it's not pure, neutral gray. Moreover, this monitor rendered everything but the pale shades of blues, reds and purples as black. Unlike modern monochrome, which will just make them appropriately dark grays.

This was rather memorable when playing Descent for example, as the game's Martian levels consisting of lots of red walls were rendered as pitch black by that monitor.

My question is: does anyone have an idea what the color standard for that VGA black and white monitor could be? I've got a few hunches from a friend that it might be CsRGB or maybe YUV or YIQ, but the conversion of an image to CsRGB proved that it was not that at the very least.

And last but not least - whatever that display format is, can it be emulated somehow on modern monitors? Thanks!

Reply 1 of 2, by Tiido

User metadata
Rank l33t
Rank
l33t

It seems it justs uses non standard weighting on the RGB mixer, it is a matter or resistor choices in the mixing circuit and likely just uses normal E12 series parts there rather than tries to get the correct luminance mix. It probably isn't difficult to figure out the weighting ratios that produce the result the monitor produces.

Yellow-brown look has to do with the phosphor chosen for the tube. Simulating it on a color tube shouldn't be a challenge, especially when the monitor has user adjustable RGB levels.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜