User:4throck/sandbox

= Gerald the Fearless = Gerald the Fearless

= Coimbra =

= Edit =

colors

 * {| class="wikitable" style="text-align: center;"


 * +SAM Coupé color palette and bitmask
 * style="color: white; background-color: #000000; width: 45pt;" |
 * style="color: white; background-color: #000049; width: 45pt;" |
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 * style="color: white; background-color: #490049; width: 45pt;" |
 * style="color: white; background-color: #004900; width: 45pt;" |
 * style="color: white; background-color: #004949; width: 45pt;" |
 * style="color: white; background-color: #494900; width: 45pt;" |
 * style="color: white; background-color: #494949; width: 45pt;" |
 * style="color: white; background-color: #242424; width: 45pt;" |
 * style="color: white; background-color: #24246d; width: 45pt;" |
 * style="color: white; background-color: #6d2424; width: 45pt;" |
 * style="color: white; background-color: #6d246d; width: 45pt;" |
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 * style="color: white; background-color: #246d6d; width: 45pt;" |
 * style="color: white; background-color: #6d6d24; width: 45pt;" |
 * style="color: white; background-color: #6d6d6d; width: 45pt;" |
 * style="color: white; background-color: #000092; width: 45pt;" |
 * style="color: white; background-color: #0000db; width: 45pt;" |
 * style="color: white; background-color: #490092; width: 45pt;" |
 * style="color: white; background-color: #4900db; width: 45pt;" |
 * style="color: white; background-color: #004992; width: 45pt;" |
 * style="color: white; background-color: #0049db; width: 45pt;" |
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 * style="color: white; background-color: #6d6db6; width: 45pt;" |
 * style="color: white; background-color: #6d6dff; width: 45pt;" |
 * style="color: white; background-color: #920000; width: 45pt;" |
 * style="color: white; background-color: #920049; width: 45pt;" |
 * style="color: white; background-color: #db0000; width: 45pt;" |
 * style="color: white; background-color: #db0049; width: 45pt;" |
 * style="color: white; background-color: #924900; width: 45pt;" |
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 * style="color: white; background-color: #db4900; width: 45pt;" |
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 * style="color: white; background-color: #db0092; width: 45pt;" |
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 * style="color: white; background-color: #924992; width: 45pt;" |
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 * style="color: black; background-color: #ff6dff; width: 45pt;" |
 * style="color: white; background-color: #009200; width: 45pt;" |
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 * style="color: white; background-color: #499200; width: 45pt;" |
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 * style="color: white; background-color: #00db00; width: 45pt;" |
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 * style="color: white; background-color: #49db00; width: 45pt;" |
 * style="color: black; background-color: #49db49; width: 45pt;" |
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 * style="color: white; background-color: #24b66d; width: 45pt;" |
 * style="color: white; background-color: #6db624; width: 45pt;" |
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 * style="color: black; background-color: #24ff6d; width: 45pt;" |
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 * style="color: black; background-color: #b6ff24; width: 45pt;" |
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 * style="color: black; background-color: #ffff24; width: 45pt;" |
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 * style="color: black; background-color: #9292db; width: 45pt;" |
 * style="color: black; background-color: #db9292; width: 45pt;" |
 * style="color: black; background-color: #db92db; width: 45pt;" |
 * style="color: black; background-color: #92db92; width: 45pt;" |
 * style="color: black; background-color: #92dbdb; width: 45pt;" |
 * style="color: black; background-color: #dbdb92; width: 45pt;" |
 * style="color: black; background-color: #dbdbdb; width: 45pt;" |
 * style="color: black; background-color: #b6b6b6; width: 45pt;" |
 * style="color: black; background-color: #b6b6ff; width: 45pt;" |
 * style="color: black; background-color: #ffb6b6; width: 45pt;" |
 * style="color: black; background-color: #ffb6ff; width: 45pt;" |
 * style="color: black; background-color: #b6ffb6; width: 45pt;" |
 * style="color: black; background-color: #b6ffff; width: 45pt;" |
 * style="color: black; background-color: #ffffb6; width: 45pt;" |
 * style="color: black; background-color: #ffffff; width: 45pt;" |
 * }
 * style="color: black; background-color: #b6b6ff; width: 45pt;" |
 * style="color: black; background-color: #ffb6b6; width: 45pt;" |
 * style="color: black; background-color: #ffb6ff; width: 45pt;" |
 * style="color: black; background-color: #b6ffb6; width: 45pt;" |
 * style="color: black; background-color: #b6ffff; width: 45pt;" |
 * style="color: black; background-color: #ffffb6; width: 45pt;" |
 * style="color: black; background-color: #ffffff; width: 45pt;" |
 * }

Hα recombination line radiation at a wavelength of 656.3 nm. - sRGB value: #ff0000

(O III in spectroscopic notation). Its emission forbidden lines in the visible spectrum fall primarily at the wavelength 500.7 nm, and secondarily at 495.9 nm.

sRGB value: #00ff87; sRGB value: #00ffc0

Forbidden lines of nitrogen ([N II] at 654.8 and 658.4 nm), sulfur ([S II] at 671.6 and 673.1 nm), and oxygen ([O II] at 372.7 nm, and [O III] at 495.9 and 500.7 nm) are commonly observed in astrophysical plasmas. The following table lists the internal signals and shows an approximation of the generated colors, as seen on a web standard sRGB monitor. Colors could be different when seen on an analog PAL CRT television. An alternate configuration of the chip allows it to output 95% luminance color bars - similar to BBC colour bars, more suited for usage in teletext decoders.

History
It was initially built into the new PS/2 Model 90 and 90 XP, and was also available as an upgrade for existing PS/2 systems, as the “IBM PS/2 XGA Display Adapter/A”.

The initial version of XGA (and its predecessor, the IBM 8514/A) expanded upon IBM's older VGA by adding support for four new screen modes (three, for the 8514/A), including one new resolution:


 * pixels in 8bit/px (256 color) palette-indexed mode.
 * pixels in direct 16 bits-per-pixel (65,536 color) RGB hi-color (required 1MB video memory option)
 * pixels with a 16-color (4bit/px) palette, using a low frequency interlaced refresh rate
 * pixels with a 256-color (8bit/px) palette, using a low frequency interlaced refresh rate (required 1MB VRAM )

Like the 8514, XGA offered fixed function hardware acceleration to offload processing of 2D drawing tasks. Both adapters allowed offloading of line-draw, bitmap-copy (BitBlt), and color-fill operations from the host CPU. XGA's acceleration was faster than 8514's, and more comprehensive, supporting more drawing primitives, the VGA-res hi-color mode, versatile "brush" and "mask" modes, system memory addressing functions, and a single simple hardware sprite typically used to provide a low CPU load mouse pointer. It was also capable of wholly independent function, as it incorporated support for all existing VGA functions and modes – the 8514 itself was a simpler add-on adapter that required a separate VGA to be present. As they were designed for use with IBM's range of fixed-frequency monitors, neither adapter offered support for SVGA modes.

Software support included drivers for OS/2 1.2 and 1.3, Windows 2.1 and 3.0, and popular software packages like AutoCAD.

XGA-2, released in 1992, added a 24-bit DAC, but this was used only to extend the available master palette in 256-color mode, e.g. to allow true 256-greyscale output instead of the 64 grey levels previously available; there was still no direct True Color mode despite the adapter featuring enough default onboard VRAM (1MB) to support it. Other improvements included the provision of the previously missing resolution (using an SVGA or multisync monitor) in up to 65,536 colors, faster screen refresh rates in all modes (including non-interlace, flicker-free output for ), and improved accelerator performance and versatility.

IBM licensed the XGA technology and architecture to certain third-party hardware developers, and its characteristic modes (although not necessarily the accelerator functions, nor the MCA data-bus interface) were aped by many others. These accelerators typically did not suffer from the same limitations on available resolutions and refresh rate, and featured other now-standard modes like (and ) at various color depths (up to 24bit/px) and interlaced, non-interlaced and flicker-free refresh rates even before the release of the XGA-2. Category:6809-based home computers Category:Thomson computers

References:
= Television systems before 1940 = Table of systems

MDA
The attribute bytes mostly behave like a bitmap:


 * Bits 0-2: 1 => underline, other values => no underline.
 * Bit 3: High intensity.
 * Bit 7: Blink

but there are eight exceptions:


 * Attributes 00h, 08h (0000 1000), 80h (1000 0000) and 88h (1000 1000) display as black space.
 * Attribute 70h (0111 0000) displays as black on green.
 * Attribute 78h (0111 1000) displays as dark green on green. In fact, depending on timing and on the design of the monitor, it may have a bright green 'halo' where the dark green and bright green bits meet.
 * Attribute F0h (1111 0000) displays as a blinking version of 70h (if blinking is enabled); as black on bright green otherwise.
 * Attribute F8h (0111 1000) displays as a blinking version of 78h (if blinking is enabled); as dark green on bright green otherwise.

{| class="wikitable" ! colspan="4" |Background ! colspan="4" |Foreground ! !Result !7 !6 !5 !4 !3 !2 !1 !0 ! ! !IB !R !G !B !I !R !G !B ! !
 * 0
 * 0
 * 0
 * 0
 * 1
 * 0
 * 0
 * 0
 * Invisible
 * 1
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0

http://www.techhelpmanual.com/87-screen_attributes.html TTL Monochrome Monitors▲    █     Black-and-White Monitors ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄█▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄  01H underline                    █ 07H normal (white on black) 07H normal (white on black)     █ 08H grey on black 09H bright underline            █ 0fH bold (bright white on black) 0fH bold (bright white on black) █ 70H reverse (black on white) 70H reverse (black on white)    █ 78H grey on white 81H blinking underline          █ 7fH bright white on white 87H blinking normal             █ 87H blinking normal 89H blinking bright underline   █ 8fH blinking bold 8fH blinking bold               █
 * Invisible
 * 1
 * 0
 * 0
 * 0
 * 1
 * 0
 * 0
 * 0
 * Invisible
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0
 * 1
 * Underline
 * 0
 * 0
 * 0
 * 0
 * 0
 * 0
 * 1
 * 0
 * Normal
 * 0
 * 1
 * 1
 * 1
 * 0
 * 0
 * 0
 * 0
 * Reverse
 * 0
 * 1
 * 1
 * 1
 * 1
 * 0
 * 0
 * 0
 * Reverse, high-intensity foreground
 * 0
 * 1
 * 1
 * 1
 * 0
 * 0
 * 0
 * 0
 * Reverse, high-intensity foreground, high-intensity background
 * 1
 * 1
 * 1
 * 1
 * 0
 * 0
 * 0
 * 0
 * Reverse, high-intensity background
 * }
 * Reverse, high-intensity foreground, high-intensity background
 * 1
 * 1
 * 1
 * 1
 * 0
 * 0
 * 0
 * 0
 * Reverse, high-intensity background
 * }
 * Reverse, high-intensity background
 * }
 * }

UK101 Character Set
Compukit UK101 character set

=Test= Digital values from https://www.cypress.com/file/74746/download

Digital color bar values
After some searching, I was able to find references for digital values, for both SD and HD 100% and 75% bars.
 * https://www.leaderamerica.com/pdf/vol03_no04.pdf
 * https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.1729-0-200504-I!!PDF-E.pdf

The first document shows the usage of signal analyzers (LV5100 for SD - http://www.valtechvideo.com/partneri/leader/LV5100D.pdf and LV5152 DA for HD - https://assets.tequipment.net/assets/1/26/Documents/Leader/lv-5152da_manual.pdf) with SD and HD patterns. Both SD and HD values for 75% and 100% bars are explicitly listed. Here's the explanation provided for the values shown:

For digital video sources, the 10-bit YCbCr values for color bars are diferent depending if we have a SD or HD signal. SD values are based on the SMPTE formula for Y from the NTSC system ( Y = 0.299R + 0.587G + 0.114B). HD values are according to SMPTE RP-177 and 274M ( based on the formula Y= 0.2126R + 0.7152G + 0.722B)

Note: Values sourced from "Leader Teleproduction Test Volume 3 Number 4 - Digital Video Levels" ; also matching Recommendation ITU-R BT.1729 (2005) for 100% SD and HD bars

Integrated speaker
Early 1980s home computers featured an integrated speaker built into the computer box. This solution was a cost-saving measure since building an RF modulator capable of encoding sound was complex and expensive. Also, the computer monitors of the time didn't feature any sound ability, so a separate solution was needed. Connecting a small speaker directly to the motherboard solved all these problems, at the expense reduced volume (there was no volume control) and poor sound fidelity.

Examples of computers that used this solution:
 * Agat (computer)
 * Acorn atom
 * ZX Spectrum (so called Beeper)

CSS wide color test

background-color: color(display-p3 1 0 0.331);