Color of text on monochrome terminals with green-on-black and amber-on-black? | Hacker News Reader

Color of text on monochrome terminals with green-on-black and amber-on-black?

retrocomputing.stackexchange.com

75 pointssusam40 comments

These monochrome Monitors displayed diffirent colors based on the mix of phosphors applied to the target area.

  'CRT (Cathode Ray Tube) Phosphors'

Phosphors : https://en.m.wikipedia.org/wiki/Phosphor

Remember, Brightness adjusts the black level, and Contrast adjusts the drive.

Picture Line-Up Generation Equipment (PLUGE) : https://en.m.wikipedia.org/wiki/Picture_line-up_generation_e...

Edited to add stuff

These types of things always make me chuckle. There are many aspects of '80s and '90s computing for which I'll wax nostalgic, but the monochrome CRTs are not among them. One could hardly have designed a better instrument for destroying eyesight, and I wince every time I need to pull out my lone remaining VT420 for anything.

I'm curious to know what you still need to pull out a hardware vt420 terminal for!

OpenVMS on VAX. There are plenty of terminal emulators out there that are 99% VT420 compatible. On *nix it's rare to notice that remaining 1%, but on VMS it's noticable.

Try xterm. Guy who develops it has a VT compatibility test suite, which most terminal emulators fail because they're mainly crappy xterm emulators. Xterm was/is written to actually emulate terminals.

xterm? Never heard of it.

In all seriousness though... sorry, friend - that's a negative re: xterm vt420 compatibility.

Quoting from the [current] author's own website at invisible-island.net/xterm/ :

"[xterm] also implements most of the control sequences for VT220, as well as selected features from other DEC terminals such as VT320, VT420, and VT520."

That "selected features" bit is why I keep the real glass one around. Paging is probably the most deficient area that I really notice.

Yes, one absolutely could! In the eighties Amstrad sold their home computers as combo with colour "monitors" (really, TV sets w/o receiver). Monochrome monitors (sharp, due to lack of shadow mask) with long persistence phosphor and hence flicker-free were balsam for the eyes in comparison.

Mind, other home computers were typically connected to the families tv set at that time ...

> colour "monitors" (really, TV sets w/o receiver).

What do you think a colour monitor is?

Good RGB monitors would have higher resolution (finer mask), higher quality, faster electronics for better signal fidelity and higher bandwidth (for higher resolution) and (depending on intended application) phosphors with longer persistence to avoid flicker.

That wasn't really a thing back then. The Amstrad CPC home computers had a tube with a finer shadowmask than the "proper" PC monitors of the day, after all.

Domestic TV shadowmasks were way way way finer than the 320x240ish resolutions common at the time, and indeed could be finer than 640-pixel horizontal resolution. Bear in mind that a broadcast-spec camera at that time ought to resolve 800 horizontal lines.

'Cathode' is a fun app if you remember the old days. Great realism, and it's adjustable, including occasional lost-sync glitches.

https://www.macupdate.com/app/mac/36568/cathode

Note: I haven't run this for a few years, and the developer's website is loading empty pages: http://www.secretgeometry.com/apps/cathode

`cool-retro-term` is being updated, and is available on MacPorts.

Yep, sadly CRT is missing a lot of the fun stuff of cathode e.g. I don't think CRT supports adjustable bitrates (baud rates), or all the mechanical sounds Cathode came with, or the hilarious "degaussing" feature.

I think cathode also had reflection using your webcam, but I may just have invented that. And I don't remember whether it had burn-in.

Either way, it was an absolute joy, so many nice details, such a shame it died.

I used to use Cathode on my iPhone. It was really nice for SSHing. Sadly it has been unusable (and at some point unavailable) for a long time now on iOS.

Not mentioned there nor in the linked https://superuser.com/questions/361297/what-colour-is-the-da... is that the IBM PC's 5151 CRT used P39, which is a 525nm long-persistence phosphor.

https://en.wikipedia.org/wiki/IBM_5151

>long-persistence phosphor.

Long persistence phosphor was also used in analog standards converters (a video camera and precision monitor),

as in the RCA slow-scan TV (SSTV) [0] from Apollo-11 [1].

Radio transmission was likely via Frequency-Shift Keying (FSK) [2],

and converted to Non-Return-to-Zero (NRZ) [3] (Raw format) on Telemetry Data tape.

The video output from the RCA analog standards converter was distributed, and also recorded on either,

Amprex 2-inch (tape width) video-recorders in either quadruplex traversal-scan VTR [4] or helicial scan VTR [5].

---

Apollo TV Camera : https://en.m.wikipedia.org/wiki/Apollo_TV_camera

Radio Corporation of America (RCA) : https://en.m.wikipedia.org/wiki/RCA

Ampex : https://en.m.wikipedia.org/wiki/Ampex

[0] Slow-Scan Television (SSTV) : https://en.m.wikipedia.org/wiki/Slow-scan_television

[1] Apollo 11 missing tapes : https://en.m.wikipedia.org/wiki/Apollo_11_missing_tapes

[2] Frequency-Shift Keying (FSK) : https://en.m.wikipedia.org/wiki/Frequency-shift_keying

[3] Non-Return-to-Zero (NRZ) : https://en.m.wikipedia.org/wiki/Non-return-to-zero

[4] Ampex 2-inch Quadruplex traversal-scan VTR : https://en.m.wikipedia.org/wiki/Quadruplex_videotape

[5] Ampex 2-inch helical-scan VTR : https://en.m.wikipedia.org/wiki/Ampex_2_inch_helical_VTR

[6] Video Tape Recorder (VTR) : https://en.m.wikipedia.org/wiki/Video_tape_recorder

---

Also long-persistence phosphor was also used in Kinescope (Kine), video to film converters.

: https://en.m.wikipedia.org/wiki/Kinescope

The Epson QX-10’s monitor also used long persistence phosphor in its 640x400 monochrome monitor. It took some getting used to, but looked nice.

The QX-10 was notable for a lot of people due to ValDocs, a WYSIWYG office suite. It also had an optical mouse the used a gridded mousepad.

I have a Hameg HM604/HM605 oscilloscope that has an orange long persistence phosphor.

This should be easy to determine by looking up the phosphors and seeing what colors they admit. Here's a chart:

https://www.phosphor-technology.com/crt-phosphors/

P1 phosphors were green; P3 were amber

In my terminals I use #7fff7f for green and #daa520 (X11 color "goldenrod") for amber. The matches, to me, are pretty close (my brain's reference for the green is a TRS-80 Model 16 with the brightness up).

palegoldenrod is stuck in my brain for some reason.

Does golden rod mean something other than what it sounds like? A tube of gold? What is colourwise peculiar about a golden rod?

> Does golden rod mean something other than what it sounds like?

"Goldenrod is a common name for many species of flowering plants in the sunflower family" - https://en.wikipedia.org/wiki/Goldenrod

Although the picture there looks more yellow than amber.

Ah hah! Thank you

Also, https://en.wikipedia.org/wiki/Goldenrod_(color)#Pale_goldenr... .

Added as an X11 color name in 1989, replacing the name "OldGoldenrod". https://cgit.freedesktop.org/~alanc/xc-historical/commit/xc/... .

it sounds like the danish word for carrot: "gulerod" which translates to "yellow root".

I guess I am that old: I started computing on a green-on-black Apple ][, and later moved to unix on a VT320 terminal. I have stuck with green-on-black in my terminal ever since. I love to work in a darkish room, and thus also like my desktop dark to avoid getting blinded by my screen. I'm pretty happy with the "dark mode" movement of the last few years!

Also, I wear glasses and find that white-on-black suffers quite a lot from chromatic aberration; green-on-black does not have this problem and results in crispy sharp text on any brightness level.

Wow, I like green-on-black so much that I config my terminal and username for it haha. Great post!

Amber on black makes me feel really comfortable, so that's how i set up mine

When I was 6 to 8 years old, the library at my school had monochrome terminals with amber text, and the library back then was so comfortable and quiet, so I have always associated amber on black with that nostalgic comfy feeling

Definitely some nostalgia for me, too. I remember using VT-220's with amber on black in college, logging into old Ultrix boxes.

Slightly OT, I remember a non-crt, the Toshiba 5200 (which was more than a laptop a transportable as it needed mains connection), plasma screen that had a distinctive (slightly darker than amber CRT's) orange that was very readable.

http://laptop.pics/toshiba-t5200100/

My terminal under FreeBSD is setup to be amber, though I basically guessed at the color code.

I used info in this article when I made this VSCode-theme a couple of years ago: https://vscodethemes.com/e/krueger71.crt-themes/crt-amber?la...

I tried to coax all elements in VSCode to use only two colors (background and foreground) with the foreground in only a few different intensities. It might give a CRT-vibe to some.

The theme is due for an update since newer VSCode has elements that aren't styled correctly.

I've tried many different text color combinations but I always go back to pure yellow on black. Something about it is just easy on the eyes.

It's just a shame that WBGR OLEDs don't allow this to be a useable option.

https://reddit.com/r/OLED_Gaming/comments/ynf2b8/lg_c2_42_ho...

Pretty sure your confusion and why people are confounded by your comments is because you're calling the layout WBGR but it seems to be RWBG.

There are no only red or green pixels in your image. The red and green sub pixels are just far apart within a pixel. Greens just happen to be close to the reds of the neighboring pixel.

The issue is that the display is trying to correct for the sub-pixel layout by interpolating over it. Users are insisting this isn't the case and that there is instead a static phase offset (ie that the red channel is from the pixel to the left and the green channel is from the pixel to the right). This might be the result in practice in the one case of yellow-gray transition, but it is not the fundament cause.

Anyway, all of this nuance isn't of interest to reddit posters. They're more interested in being the smartest person in the room and shouting down any intellectually stimulating discussion. I was just hoping the high exposure forum might draw out some hidden trick to fixing this issue.

I think they keep saying the opposite and you keep talking past them and insulting them.

Seems like the posters are saying every pixel is showing yellow but the sub pixel layout (not any artificial sub-pixel sampling) produces the artifact you're seeing.

|R--G|R--G|R--G|R--G|R--G|

That sub-pixel arrange isn't correct though, as seen by closely inspecting other transitions.

I have not insulted them. They have been rather hostile and at most I mocked in response to comment that only contained insult.

Also, the sub-pixel layout is indeed WBGR. This is easier to see in the green-gray horizontal transition.

https://imgur.com/a/a1UL57t

Not sure how that shows its WBGR vs RWBG. Besides, your claim is that something is doing sub-pixel operations so using other color patterns would be just as inconclusive as the yellow you're posting about, no?

Looking at spec sites and they say its RWBG. https://www.rtings.com/monitor/reviews/lg/42-c2-oled

Orange on black with Jetbrains Mono. Took me a while to get vim under tmux via ssh to look right, but overall, so easy on the eyes, so distinct.

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