65
votes
Why didn't early color TV sets accept RGB input?
When colour television broadcasts began (1960s, in the UK; perhaps a little earlier in North America?) there weren't any local devices that customers might want to use. Broadcast TV was the only ...
- 1,687
59
votes
Accepted
Why were animated screensavers used instead of a black screen on CRT monitors?
To elaborate on Jon Custer's comment: yes, for protecting the display against burn-in, a black screen would do just as well or better as any "screensaver". However, the graphical effects ...
- 1,150
50
votes
Why did 80x25 become the text monitor standard?
Where did the 80x25 text terminal size come from?
Quick answer: It's one Punch Card Per Line
Resulting in 24/25 lines (cards) per screen when using a 4:3 tube and a reasonable font as dictated by ...
- 236k
50
votes
Accepted
What does the 7 segment number mean on my CRT monitor?
It's indicating the display resolution using an approximation of the number of vertical scanlines. So 7 means you are probably running in 1024x768. It's not entirely consistent because some modes are ...
- 4,082
40
votes
Why did some video games apparently use "interlaced" video modes?
Indeed, early devices such as C64, NES, or IBM PC with CGA adapter did not use interlacing, but simply sent 240p to the TV. And later devices such as the Amiga could send either 480i or 240p.
But TVs ...
- 37.2k
37
votes
Why were animated screensavers used instead of a black screen on CRT monitors?
A blank screen would have been just as effective for protecting the CRT from the burn-in associated with a static display. However, for a time in the late 80's through 1990's, certain popular ...
- 61.5k
32
votes
Accepted
Square pixels and TV output
CRT TVs are analog devices, there is no "pixel", but the size of the spot limits the resolution of the image, as the size of silver nitrate crystals limits the resolution of photo films.
Several ...
- 3,745
28
votes
Accepted
What is the difference between the Commodore 1701 and the 1702?
The 1701 and 1702 are virtually identical. They have the same specs, tube, inputs, casing, and manufacturer. The only real difference is the 1701 is older (1982 to early '83, 1702 is late '83) and the ...
- 4,650
27
votes
Accepted
Why did 80x25 become the text monitor standard?
A lot of early PCs and terminals were designed to use either TVs or monitors that were built around CRTs that were built to the same specifications as TVs. While (traditional standard definition) TVs ...
- 13k
27
votes
Is it possible to swap the Apple IIc's monochrome CRT tube for a color one?
If you don't know, then the answer is "no".
It certainly is possible to get a color CRT tube and matching electronics and fit them into a cleared out case.
However, if you have to ask people on the ...
- 295
26
votes
Samsung SyncMaster 3 cannot show resolutions up from 800x600 despite manual saying otherwise
According to your manual, the monitor can only do 1024x768 interlaced; I strongly suspect you're sending 1024x768 progressive (i.e. non-interlaced).
- 561
24
votes
Adjusting focus for old CRT monitors
The EHT (extra-high-tension) circuits used to drive colour CRT displays run at 25kV (kilo-volts), and the capacitors contain enough stored charge to kill you stone dead if you touch the wrong thing, ...
- 2,849
23
votes
Accepted
Computers with integrated monitor (all-in-one form factor)
It's a little cheaper to build all-in-one units because you only need one cabinet and one power supply, and you need fewer cables and connectors and supporting electronics.
And back then, people didn'...
- 17.6k
23
votes
Accepted
Can the wrong sync frequency really destroy a CRT monitor?
Horizontal deflection circuit is intended to make linearly increasing current in the deflection coil. At the end of ray scanning from left to right, the deflection coil should be re-magnetized in a ...
- 11.4k
23
votes
Why didn't early color TV sets accept RGB input?
Early colour TVs predated VCRs and home computers by many years. Even if it did not cost much, adding an RGB input would still be a cost for something that no one would use. However, it would have ...
- 2,173
23
votes
Why didn't early color TV sets accept RGB input?
Many TV designs up into the 1970s were so called live chassis designs, which used one leg of the mains input as a reference ground. This saved materials and weight - given some early color TVs used ...
- 5,842
21
votes
What is the correct name for the old green/amber-on-black monitors, and what are the best vintage models to look for used?
Are they called "monochrome" monitors, or something else?
Yes. Monochrome covers all that paint in Amber, Green, Blue or white on black.
What I want is one of those with glowing green ...
- 236k
19
votes
Was the picture area of a CRT a parallelogram (instead of a true rectangle)?
Canonically in NTSC standards the drawn lines are tilted slightly so that the start of the odd field starting at the left is perfectly level with the top of the even field starting in the middle ...
- 291
19
votes
Accepted
Why does my CRT whine?
My Amstrad CTM644 CRT 'monitor', makes a high pitched whine [...] My research indicates that this is just the scanning frequency of the tube,
The ~15 kHz line frequency is the most likely source. ...
- 236k
18
votes
Accepted
What causes the monitor to reduce to four lines on BK 0010 Focal?
After pressing "AP2+CБP" key combination computer switches to extended memory mode, in which screen is reduced to 1/4 of original size giving about 12Kb memory of screen RAM to user (extending user ...
- 196
18
votes
Accepted
Did any computer allow overscan on a CRT monitor?
The Commodore Amiga (all models) had hardware support for overscan on CRTs. This was accessible to the user through the Preferences settings, as shown in the dialog panel below.
The Preferences ...
- 61.5k
18
votes
Accepted
What's the name of this CRT monitor?
It’s a regular 80s-era TV set, specifically a Ferguson MC01 (from a 1986 Argos catalogue, see this article): the buttons are volume, brightness, contrast, colour, and channel selection buttons. This ...
- 131k
18
votes
Physical resolution and control of old VGA (color) CRT monitors
What was the phosphor resolution?
The usual specification quoted for CRT resolution is the 'dot pitch', or distance between groups of RGB phosphor dots. Here are some examples of IBM monitors ...
- 6,773
17
votes
Accepted
What is the correct name for the old green/amber-on-black monitors, and what are the best vintage models to look for used?
A "monochrome" screen refers to any display which only displays one colour, based on the type of phosphor used. The type you are after is more specifically called a "green screen" ...
- 574
17
votes
Accepted
Choosing a monochrome color at the monitor?
A form of this was used extensively for avionics displays. Known as the penetron (stop giggling), the CRT used a single gun and dual phosphor coatings (red and green). Each frame was drawn in two ...
- 9,460
17
votes
Why did some video games apparently use "interlaced" video modes?
TL;DR:
It's not about what a console can deliver as it is what a TV can display. Classic (pre digital) TV sets could only receive and display interlaced frames. So no sense in producing a non ...
- 236k
16
votes
Why did 80x25 become the text monitor standard?
The 80 columns comes via IBM terminals such as the 3270, which themselves got it from IBM punched cards. There was no particular reason to pick 80 over some other width for punched cards except that ...
- 11.6k
16
votes
Accepted
What's the name of this Apple monitor
NEC Character Display, Model JB-1201M(A).
It’s a 12” monochrome green display, manufactured in Japan circa 1981. Approximate dimensions are 14” x 12” x 11 1/2”.
Further details found at:
https://www....
- 176
15
votes
Accepted
Why not SCART for early color monitors
Caveat: 'Why Not' questions are like 'What If' and rarely have a definite answer. It's an (educated) speculation at best.
In case of interface and connectors, NIH (Not Invented Here) is a big issue. ...
- 236k
15
votes
Was the picture area of a CRT a parallelogram (instead of a true rectangle)?
IIRC, the electron gun was actually installed in a position where it was rotated slightly relative to the tube, to compensate for this effect, so the scan lines did end up being horizontal.
- 63.8k
Only top scored, non community-wiki answers of a minimum length are eligible