List of 8-bit computer hardware graphics

Level 1

World System Teletext Level 1 (1976) uses a 3-bit RGB, 8-color palette. Teletext has 40×25 characters per page of which the first row is reserved for a page header. Every character cell has a background color and a text color. These attributes along with others are set through control codes which each occupy one character position. Graphics characters consisting of 2×3 cells can used following a graphics color attribute. Up to a maximum of 72×69 blocky pixels can be used on a page.

Apple II series

The Apple II series features a 16-color composite video palette, based on the YIQ color space used by the NTSC color TV system.^[1][2] The Apple II features "lowres" and "hires" modes.

Number — name	Y	Pb (rel.)	Pr (rel.)	Number — name	Y	Pb (rel.)	Pr (rel.)
0 — black	0	0	0	8 — brown	0.25	−0.5	0
1 — magenta	0.25	0	0.5	9 — orange	0.5	−1	1
2 — dark blue	0.25	0.5	0	10 — grey #2	0.5	0	0
3 — purple	0.5	1	1	11 — pink	0.75	0	0.5
4 — dark green	0.25	0	−0.5	12 — green	0.5	−1	−1
5 — grey #1	0.5	0	0	13 — yellow	0.75	−0.5	0
6 — medium blue	0.5	1	−1	14 — aqua	0.75	0	−0.5
7 — light blue	0.75	0.5	0	15 — white	1	0	0

The Apple II features "lo-res" and "hi-res" modes. The 40x48 pixel lo-res mode allowed 15 different colors plus a duplicate gray.^[3] The majority of Apple graphic applications used the hi-res mode, which had 280×192 pixels (effectively 140x192 on a color monitor). The hi-res mode allowed six colors: black, white, blue, orange, green and purple.

VIC-20

The Commodore VIC-20 features a MOS Technology VIC chip which produces a 16-color YPbPr composite video palette.^[8] The palette lacks any intermediate shade of gray, and it has only 5 levels of luminance.

The VIC-20 lacks any true graphic mode, but a 22×11 text mode with 200 definable characters of 8×16 bits each arranged as a matrix of 20×10 characters is usually used instead, giving a 3:2(NTSC)/5:3(PAL) pixel aspect ratio, 160×160 pixels, 8-color "high-res mode" or a 3:1(NTSC)/10:3(PAL) pixel aspect ratio, 80×160 pixels, 10-color "multicolor mode".

Sample image

In the 8-color high-res mode, every 8×8 pixels can have the background color (shared for the entire screen) or a free foreground color, both selectable among the first eight colors of the palette. In the 10-color multicolor mode, a single pixel of every 4×8 block (a character cell) may have any of four colors: the background color, the auxiliary color (both shared for the entire screen and selectable among the entire palette), the same color as the overscan border (also a shared color) or a free foreground color, both selectable among the first eight colors of the palette.

Multicolor mode	High-res mode

Number — name	Y	Pb (rel.)	Pr (rel.)	Number — name	Y	Pb (rel.)	Pr (rel.)
0 — black	0	0	0	8 — orange	0.5	−0.707	0.707
1 — white	1	0	0	9 — light orange	0.75	−0.707	0.707
2 — red	0.25	−0.383	0.924	10 — light red	0.5	−0.383	0.924
3 — cyan	0.75	0.383	−0.924	11 — light cyan*	1	0.383	−0.924
4 — purple	0.5	0.707	0.707	12 — light purple	0.75	0.707	0.707
5 — green	0.5	−0.707	−0.707	13 — light green	0.75	−0.707	−0.707
6 — blue	0.25	1	0	14 — light blue	0.5	1	0
7 — yellow	0.75	−1	0	15 — light yellow*	1	−1	0

Note: the colors marked with an asterisk (*) are out of the RGB gamut.

C-64

The MOS Technology VIC-II is used in the Commodore 64 (and Commodore 128 in 40-column mode), and features a 16-color YPbPr composite video palette.^[9] This palette is largely based on that of the VIC, but it substitutes three colors by three levels of gray, and there are more values for the luminance. When displayed over an analog NTSC composite video output, the actual resulting colors are more vivid.

Sample image	Color test chart	Color palette	C64 palette on NTSC (Sony CXA2025 decoder matrix)
			[10]

The Commodore 64 has two graphic modes: Multicolor and High Resolution.

In the Multicolor 160×200, 16-color mode, every cell of 4×8, 2:1 aspect ratio pixels can have one of four colors: one shared with the entire screen, the two background and foreground colors of the corresponding text mode character, and one more color also stored in the color RAM area, all of them freely selectable among the entire palette.

In the High Resolution 320×200, 16-color mode, every cell of 8×8 pixels can have one of the two background and foreground colors of the correspondent text mode character, both freely selectable among the entire palette.

16-color multicolor mode	16-color High-res mode

Number — name	Y	Pb (rel.)	Pr (rel.)	Number — name	Y	Pb (rel.)	Pr (rel.)
0 — black	0	0	0	8 — orange	0.375	−0.707	0.707
1 — white	1	0	0	9 — brown	0.25	−0.924	0.383
2 — red	0.313	−0.383	0.924	10 — light red	0.5	−0.383	0.924
3 — cyan	0.625	0.383	−0.924	11 — dark grey	0.313	0	0
4 — purple	0.375	0.707	0.707	12 — grey	0.469	0	0
5 — green	0.5	−0.707	−0.707	13 — light green	0.75	−0.707	−0.707
6 — blue	0.25	1	0	14 — light blue	0.469	1	0
7 — yellow	0.75	−1	0	15 — light grey	0.625	0	0

C-16 and Plus/4

The MOS Technology TED was used in the Commodore 16 and Commodore Plus/4. It has a palette of 121 YPbPr composite video colors^[11] consisting of sixteen hues (including black and white) at eight luminance levels. Black is the same color at every luminance level, so there are not 128 different colors. On the Plus/4, twelve colors formed a "default" palette of sorts accessible through keyboard shortcuts;^[12] these colors are underlined in the table below (RGB equivalents at a saturation level of 34%).

The Commodore 16 and Plus/4 have two graphic modes very similar to those of the Commodore 64: Multicolor and High Resolution.

In the Multicolor 160×200, 121-color mode, every cell of 4×8, 2:1 aspect ratio pixels can have one of four colors: two shared with the entire screen and the two background and foreground colors of the correspondent text mode character, all of them freely selectable among the entire 121-color palette (hue 0 to 15 and luminance 0 to 7 are set individually for any of them).

In the High Resolution 320×200, 121-color mode, every cell of 8×8 pixels can have one of the two background and foreground colors of the corresponding text mode character, both freely selectable among the entire 121-color palette (again setting both the hue and the luminance).

121-color Multicolor mode	121-color High-res mode

		luma #	0	1	2	3	4	5	6	7
		Y	0.125	0.25	0.375	0.5	0.625	0.75	0.875	1
hue #	Pb (rel.)	Pr (rel.)	.	.	.	.	.	.	.	.
0 — black	0	0	0,0	0,1	0,2	0,3	0,4	0,5	0,6	0,7
1 — white	0	0	1,0	1,1	1,2	1,3	1,4	1,5	1,6	1,7
2 — red	−0.383	0.924	2,0	2,1	2,2	2,3	2,4	2,5	2,6*	2,7*
3 — cyan	0.383	−0.924	3,0*	3,1	3,2	3,3	3,4	3,5	3,6	3,7*
4 — purple	0.707	0.707	4,0*	4,1	4,2	4,3	4,4	4,5	4,6*	4,7*
5 — green	−0.707	−0.707	5,0*	5,1	5,2	5,3	5,4	5,5	5,6*	5,7*
6 — blue	1	0	6,0	6,1	6,2	6,3	6,4	6,5*	6,6*	6,7*
7 — yellow	−1	0	7,0*	7,1*	7,2	7,3	7,4	7,5	7,6	7,7*
8 — orange	−0.707	0.707	8,0*	8,1	8,2	8,3	8,4	8,5	8,6*	8,7*
9 — brown	−0.924	0.383	9,0*	9,1*	9,2	9,3	9,4	9,5	9,6	9,7*
10 — yellow-green	−0.924	−0.383	10,0*	10,1*	10,2	10,3	10,4	10,5	10,6	10,7*
11 — pink	0	1	11,0	11,1	11,2	11,3	11,4	11,5	11,6*	11,7*
12 — blue-green	0	−1	12,0*	12,1	12,2	12,3	12,4	12,5	12,6	12,7*
13 — light blue	0.707	−0.707	13,0*	13,1	13,2	13,3	13,4	13,5	13,6*	13,7*
14 — dark blue	0.924	0.383	14,0	14,1	14,2	14,3	14,4	14,5*	14,6*	14,7*
15 — light green	−0.383	−0.924	15,0*	15,1	15,2	15,3	15,4	15,5	15,6*	15,7*

Note: every YPbPr color marked with an asterisk (*) is out of the RGB gamut. This was intentionally done by the designers to achieve the maximum number of colors for composite video monitors.

Tandy Color Computer 3

The Tandy Color Computer 3 could display all of the modes of the Tandy Color Computer 1 and 2, except the Semigraphics modes, plus resolutions of 160, 256, 320, or 640 pixels wide by 192 to 225 lines from a palette of 64 colors. The 320 mode allowed 16 simultaneous colors, while the 640 mode allowed 4.

ZX Spectrum

The ZX Spectrum (and compatible) computers use a variation of the 4-bit RGBI palette philosophy. This results in each of the colors of the 3-bit palette to have a basic and bright variant, with the exception of black. This was accomplished by having a maximum voltage level for the bright variant, and a lower voltage level for the basic variant. Due to this, black is the same in both variants.

The attribute byte associated to every 8×8 pixel cell dedicates (from LSB to MSB): three bits for the background color; three bits for the foreground color; one bit for the bright variant for both, and one bit for the flashing effect (alternate foreground and background colors evenly in time). So the colors are not selectable as indices of a true palette (there are not color numbers 8 to 15).

The color numbers can be employed with the following statements to choose:

• BORDER n, the color for the surrounding area outside the pixel graphical area.
• PAPER n, the background (pixel bit value of 0) color for an 8×8 pixel cell.
• INK n, the foreground (pixel bit value of 1) color for an 8×8 pixel cell.

Simulated image	Sample image

Color number	Binary value	BRIGHT 0	BRIGHT 1
0	000	black	black
1	001	basic blue	bright blue
2	010	basic red	bright red
3	011	basic magenta	bright magenta
4	100	basic green	bright green
5	101	basic cyan	bright cyan
6	110	basic yellow	bright yellow
7	111	basic white	bright white

CPC series

The Amstrad CPC 464/664/6128 series of computers generate the available palette with 3 levels (not bits) for every RGB primary. Thus, there are 27 different RGB combinations, from which 16 can be simultaneously displayed in low resolution mode, four in medium resolution mode and two in high resolution mode.^[14]

Simulations of actual images on the Amstrad's color monitor in each of the modes (160×200, 16 colors; 320×200, 4 colors and 640×200, 2 colors) follows. A cheaper green monochrome display was also available from the manufacturer; in this case, the colors are viewed as a 16-tone green scale, as shown in the last simulated image, as it interprets the overall brightness of the full colour signal, instead of only considering the green intensity as might, e.g., the Philips CM8833 line.

2 colors	4 colors	16 colors	16-tone green scale

0 – Black (5)	1 – Blue (0,14)	2 – Bright blue (6)	3 – Red	4 – Magenta	5 – Violet	6 – Bright red (3)	7 – Purple	8 – Bright magenta (7)
9 – Green	10 – Cyan (8)	11 – Sky blue (15)	12 – Yellow (9)	13 – Grey	14 – Pale blue (10)	15 – Orange	16 – Pink (11)	17 – Pale magenta
18 – Bright green (12)	19 – Sea green	20 – Bright cyan (2)	21 – Lime green	22 – Pale green (13)	23 – Pale cyan	24 – Bright yellow (1)	25 – Pale yellow	26 – Bright white (4)

The number in parentheses means the primary ink number for the Locomotive BASIC PEN, PAPER and INK statements (that is, "(1)" means ink #1 defaults to this color). Inks can also have a secondary color number, meaning they flash between two colors. By default, ink #14 alternates between colors 1 and 24 (blue and bright yellow) and ink #15 alternates between colors 11 and 16 (sky blue and pink). In addition, the paper defaults to ink #0 and the pen to ink #1, meaning bright yellow text on a blue background.

Original MSX

The MSX compatible computers feature a Texas Instruments TMS9918 chip which uses a proprietary 15-color YPbPr-encoded palette^[15] plus a transparent color, intended to be used by the hardware sprites and simple video overlay. When used as an ordinary background color, it is rendered using the same color as the screen border.

The MSX series has two graphic modes. The MSX BASIC Screen 3 mode is a low-resolution mode with 15 colors, in which every pixel can be any of the 15 available colors. Screen mode 2 is a high-resolution mode with 15 colors, in which every eight consecutive pixels can be one of two out of the 15 available colors.

15-color screen mode 3	15-color screen mode 2

Number — name	Y	Pb (rel.)	Pr (rel.)	Number — name	Y	Pb (rel.)	Pr (rel.)
0 — transparent	0	0	0	8 — medium red	0.53	−0.377	0.868
1 — black	0	0	0	9 — light red	0.67	−0.377	0.868
2 — medium green	0.53	−0.509	−0.755	10 — dark yellow	0.73	−0.755	0.189
3 — light green	0.67	−0.377	−0.566	11 — light yellow	0.80	−0.566	0.189
4 — dark blue	0.40	1	−0.132	12 — dark green	0.47	−0.453	−0.642
5 — light blue	0.53	0.868	−0.075	13 — magenta	0.53	0.377	0.491
6 — dark red	0.47	−0.321	0.679	14 — gray	0.80	0	0
7 — cyan	0.73	0.434	−0.887	15 — white	1	0	0

MSX2

The MSX2 series features a Yamaha V9938 video chip, which manages a 9-bit RGB palette (512 colors) and has some extended graphic modes. Although its graphical capabilities are similar, or even better than of those of 16-bit personal computers, MSX2 and MSX2+ (see below) are pure 8-bit machines.

Screen mode 6 is a 512×212-pixel mode with a 4-color palette chosen from the available 512 colors.

Screen modes 5 and 7 are high-resolution 256×212-pixel and 512×212-pixel modes, respectively, with a 16-color palette chosen from the available 512 colors. Each pixel can be any of the 16 selected colors.

Screen mode 8 is a high-resolution 256×212-pixel mode with an 8-bit color depth, giving a palette of 256 colors.^[16] From the MSB to LSB, there are three green bits, three red bits, and two blue bits. This mode uses half of the available colors overall, and can be considered a palette in its own right.

4-color screen mode 6	16-color screen mode 5	256-color screen mode 8

MSX2+

The MSX2+ series features a Yamaha V9958 video chip which manages a 15-bit RGB palette internally encoded in YJK (up to 19,268 different colors from the 32,768 theorically possible)^[17] and has additional screen modes. Although its graphical capabilities are similar, or even better than of those of 16-bit personal computers, MSX2 (see above) and MSX2+ are pure 8-bit machines. YJK color encoding can be viewed as a lossy compression technique; in the RGB to YJK conversion, the average red and green levels are preserved, blue is subsampled. As a result of every four pixels sharing a chroma value, in mode 12 it is not possible to have vertical lines of a single color. This is only possible in modes 10 and 11 due to the additional 16-color direct palette. This can be used to mix 16 indexed colors with a rich colorful background, in what can be considered a primitive video overlay technique.

Screen modes 10 & 11 – 12,499 YJK colours plus a 16-color palette. In this mode, the YJK technique encodes 16 levels of luminance into the four LSBs of each pixel and 64 levels of chroma, from −32 to +31, shared across every four consecutive pixels and stored in the three higher bits of the four pixels. If the fifth bit of the pixel is set, then the lower four bits of the pixel points to an index in the 16-color palette; otherwise, they specify the YJK luminance level of the pixel.

Screen mode 12 is similar to modes 10 and 11, but uses five bits to encode 32 levels of luminance for every pixel, thus it does not use an additional palette and, with YJK encoding, 19,268 different colors can be displayed simultaneously with 8-bit color depth.

Screen mode 10 & 11	Screen mode 12

CGA

The Color Graphics Adapter (CGA) outputs what IBM called "digital RGB"^[18] (that is, the R, G, B (and I) signals from the graphics card to the monitor can each only have two states: on or off). CGA supports a maximum of 16 colors. However, its 320×200 graphics mode is restricted to fixed palettes containing only four colors, and the 640×200 graphic mode is only two colors. 16 colours are only available in text mode or the "tweaked text" 160×100 mode. A different set of 16 colours is available in composite mode with composite monitor.

The full standard RGBI palette is a variant of the 4-bit RGBI schema. Although the RGBI signals have only two states, the CGA color monitor decodes them as if RGB signals had four levels. Darker colors are the basic RGB 2nd level signals except for brown, which is dark yellow with the level for the green component halved (1st level). Brighter colors are made by adding a uniform intensity one level signal to every RGB signal of the dark ones reaching the 3rd level (except dark gray which reaches only the 1st level), and in this case yellow is produced as if the brown were ordinary dark yellow.

0 — black	8 — dark gray
1 — low blue	9 — high blue
2 — low green	10 — high green
3 — low cyan	11 — high cyan
4 — low red	12 — high red
5 — low magenta	13 — high magenta
6 — brown	14 — yellow
7 — light gray	15 — white

The color numbers above are not arbitrary; they are based on the following bitmask:

Binary	Base-Ten	Color
1000	8	intense, high, or bright
0100	4	red
0010	2	green
0001	1	blue

A few earlier non-IBM compatible CGA monitors lack the circuitry to decode color numbers as of four levels internally, and they cannot show brown and dark gray. The above palette is displayed in such monitors as follows:

0 — black	8 — black
1 — low blue	9 — high blue
2 — low green	10 — high green
3 — low cyan	11 — high cyan
4 — low red	12 — high red
5 — low magenta	13 — high magenta
6 — low yellow	14 — yellow
7 — light gray	15 — white

• 16-color palette modes

16-color, 80×50 mode	16-color, 160×100 mode

• 2-color palette mode

In the 640×200 graphic mode (BIOS mode number 6), every pixel has only a single bit. A value of 0 is always black, while a value of 1 is the color set in the bits 0 to 3 (bit3=I, bit2=R, bit1=G, bit0=B) of the CRT Color Selector Register (in 3D9h). The foreground color can be set with a call to the function 0Bh of the BIOS's INT 10h. The default foreground color is white.

2-color palette mode

0 — black

1 — [user-defined]

• 4-color palette modes

In the 320×200 graphics mode, every pixel has two bits. A value of 0 is always a selectable background-plus-border color (with the same register and/or BIOS call used for the foreground color in the 640×200 graphic mode; black by default), and the three remaining values 1 to 3 are indices to one of the predefined color palette entries. The selection of a given fixed palette is a bit complex. There are two BIOS 320×200 graphic modes. The mode number 4 has enabled the composite color burst output (CRT Mode Control Register in 3D8H has cleared the bit 2), and the mode number 5 has it disabled (bit 2 set on the register). This gives two sets of palettes, one for "digital RGB" color monitors and one for monochrome composite video monitors, but the last has its own colors when viewed in a color monitor. The desired video mode, 4 or 5, can be set with the function 0h of the BIOS's INT 10h. For the BIOS mode 4, two palettes can be chosen: green-red-yellow and cyan-magenta-white (that is, the former plus the blue signal). The palette is selected with bit 5 of the CRT Color Selector Register in 3D9h. A value of 1 means the cyan-magenta-white palette (known as the "palette #1" because is the default for the mode 4), and 0 is the green-red-yellow (known as the "palette #2"). It can be set with the function 0Bh, subfunction 1, of the BIOS's INT 10h. The palette for the BIOS mode 5 is always cyan-red-white. In every of the 4 and 5 mode palettes, a low or high intensity can be chosen with the bit 4 of the CRT Color Selector Register in 3D9h. A value of 0 means the low intensity, and 1 means the high. No BIOS call exist to switch between the two intensity modes.

	Mode 4, palette #1	Mode 4, palette #2	Mode 5
Low intensity
High intensity
Simulated Grayscale

Mode 4, palette #1, low intensity	0 — [user-defined]	1 — cyan	2 — magenta	3 — light grey
Mode 4, palette #1, high intensity	0 — [user-defined]	1 — bright cyan	2 — bright magenta	3 — bright white
Mode 4, palette #2, low intensity	0 — [user-defined]	1 — green	2 — red	3 — brown
Mode 4, palette #2, high intensity	0 — [user-defined]	1 — bright green	2 — bright red	3 — yellow
Mode 5, low intensity	0 — [user-defined]	1 — cyan	2 — red	3 — light grey
Mode 5, high intensity	0 — [user-defined]	1 — bright cyan	2 — bright red	3 — white

PCjr and Tandy 1000 series

The IBM PCjr, and near compatible Tandy 1000 series, feature a graphic chip known as "Video Gate Array", which is able to show all 16 CGA colors simultaneously on screen in the extended low-res graphic modes. This graphic adapter is better known as Tandy Graphics Adapter. All extended PCjr/Tandy 1000 graphics modes could reassign any color index to any palette entry, for color cycling effects.