Amstrad PC - Revision history

Phi2x: /* CGA */

2025-05-12T07:57:47Z

CGA

← Older revision		Revision as of 07:57, 12 May 2025
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	=== CGA ===		=== CGA ===
	~~Enabled~~ mostly 320x200 display with a palette of 4 colours choosen between 4 combinations from 16 total colours. It also offered a text mode with character attribute based 16 colours display.		On RGBI monitors, it enabled mostly 320x200 display with a palette of 4 colours choosen between 4 combinations from 16 total colours. It also offered a text mode with character attribute based 16 colours display.

	On composite monitors or TVs, composite output enabled artifact-based NTSC colour emulation, simulating more colours (typically 16 colours simultaneously, but up to 1024 colours have been demonstrated).		On composite monitors or TVs, composite output enabled artifact-based NTSC colour emulation, simulating more colours (typically 16 colours simultaneously, but up to 1024 colours have been demonstrated).

Phi2x: /* CGA */

2025-05-12T07:56:26Z

CGA

← Older revision		Revision as of 07:56, 12 May 2025
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	=== CGA ===		=== CGA ===
	Enabled mostly 320x200 display with a palette of 4 colours choosen between 4 combinations ~~(only one colour to be chosen)~~ from 16 total colours. ~~Could~~ also ~~get~~ a text mode with character attribute based 16 colours display.		Enabled mostly 320x200 display with a palette of 4 colours choosen between 4 combinations from 16 total colours. It also offered a text mode with character attribute based 16 colours display.

			On composite monitors or TVs, composite output enabled artifact-based NTSC colour emulation, simulating more colours (typically 16 colours simultaneously, but up to 1024 colours have been demonstrated).

	The Amstrad CPC can quite be considered a custom and more versatile CGA.		The Amstrad CPC can quite be considered a custom and more versatile CGA.

Phi2x: /* VGA */

2025-05-12T07:34:38Z

VGA

← Older revision		Revision as of 07:34, 12 May 2025
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	The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits).		The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits).

	VGA could emulate all CGA and EGA modes. However, as VGA monitors no longer supported 15.7kHz ~~signals~~, CGA, EGA, and MCGA modes were line-doubled to match the monitor's capabilities.		VGA could emulate all CGA and EGA modes. However, as VGA monitors no longer supported 15.7kHz scan rates, CGA, EGA, and MCGA modes were line-doubled to match the monitor's capabilities.

	<br>		<br>

Phi2x: /* The video displays */

2025-05-12T07:33:40Z

The video displays

← Older revision		Revision as of 07:33, 12 May 2025
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	[[File:Prince of persia vga ega cga hercules.png]]		[[File:Prince of persia vga ega cga hercules.png]]

	~~The major kind of display from this~~ era ~~had~~ to ~~get~~ specific monitors~~, and those~~ were quite expensive.		During that era (late 1980s to early 1990s), different graphics standards typically required their own specific monitors which were quite expensive.

			Each graphics standard had particular signal timing and connector requirements:

			*CGA monitors needed to handle 15.7 kHz horizontal scan rates with RGBI signals
			*EGA monitors required support for 21.8 kHz scan rates with analog RGB signals
			*VGA monitors needed 31.5 kHz scan rates with a different analog RGB implementation

	=== CGA ===		=== CGA ===
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	The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits).		The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits).

	VGA could emulate all CGA and EGA modes. However, as VGA monitors no longer supported ~~15KHz~~ signals, CGA, EGA, and MCGA modes were line-doubled to match the monitor's capabilities.		VGA could emulate all CGA and EGA modes. However, as VGA monitors no longer supported 15.7kHz signals, CGA, EGA, and MCGA modes were line-doubled to match the monitor's capabilities.

	<br>		<br>

Phi2x: /* VGA */

2025-05-12T07:25:14Z

VGA

← Older revision		Revision as of 07:25, 12 May 2025
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	The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits).		The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits).

	VGA could ~~also display~~ all ~~previous modes from~~ CGA and EGA ~~cards~~. However, ~~due to~~ VGA monitors no longer ~~being able to handle~~ 15KHz, CGA and ~~EGA~~ modes were ~~typically~~ line-doubled to match the monitor's capabilities.		VGA could emulate all CGA and EGA modes. However, as VGA monitors no longer supported 15KHz signals, CGA, EGA, and MCGA modes were line-doubled to match the monitor's capabilities.

	<br>		<br>

Phi2x at 19:45, 11 May 2025

2025-05-11T19:45:05Z

← Older revision		Revision as of 19:45, 11 May 2025
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	[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]		[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]

	[[File:Amstrad-pc1512-ad.jpg\|thumb\|right\|300px\|Amstrad PC1512 ~~advertised~~]]		[[File:Amstrad-pc1512-ad.jpg\|thumb\|right\|300px\|Amstrad PC1512 advertisement]]

	[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]		[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]

Phi2x: /* The video displays */

2025-05-11T17:59:16Z

The video displays

← Older revision		Revision as of 17:59, 11 May 2025
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	= The video displays =		= The video displays =

	The 3 major kind of display from this era had to get specific monitors, and those were quite expensive.		VGA / EGA / CGA / Hercules graphics comparison:

			[[File:Prince of persia vga ega cga hercules.png]]

			The major kind of display from this era had to get specific monitors, and those were quite expensive.

	=== CGA ===		=== CGA ===

Phi2x: /* VGA */

2025-05-11T17:43:59Z

VGA

← Older revision		Revision as of 17:43, 11 May 2025
Line 53:		Line 53:

	=== VGA ===		=== VGA ===
	The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits). ~~The~~ VGA could also display all previous modes from CGA and EGA cards.		The widely used VGA mode was the MCGA : 320x200x256. When those kind of display were widely available the CGA and EGA were obsolete and the PC could start to kick Amiga and Atari ST standards out of the place. VGA could also display a 640x480x16 video mode. All those from a 262,144colour total palette (6x6x6 bits).

			VGA could also display all previous modes from CGA and EGA cards. However, due to VGA monitors no longer being able to handle 15KHz, CGA and EGA modes were typically line-doubled to match the monitor's capabilities.

	<br>		<br>

Phi2x: /* Palettes */

2025-05-11T13:38:51Z

Palettes

← Older revision		Revision as of 13:38, 11 May 2025
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	This looks quite like a ZX Spectrum palette.		This looks quite like a ZX Spectrum palette.

			Note: Color 6 is treated specially. Normally, color 6 would become dark yellow, but in order to achieve a more pleasing brown tone, special circuitry in most RGBI monitors makes an exception for color 6 and changes its hue from dark yellow to brown. Some monitors even provide a potentiometer labelled "BROWN ADJ." to adjust this color.

	*EGA palette :		*EGA palette :

Phi2x at 13:22, 11 May 2025

2025-05-11T13:22:44Z

← Older revision		Revision as of 13:22, 11 May 2025
Line 1:		Line 1:
	[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]		[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]

			[[File:Amstrad-pc1512-ad.jpg\|thumb\|right\|300px\|Amstrad PC1512 advertised]]

	[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]		[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]

← Older revision		Revision as of 19:45, 11 May 2025
Line 1:		Line 1:
	[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]		[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]

	[[File:Amstrad-pc1512-ad.jpg\|thumb\|right\|300px\|Amstrad PC1512 ~~advertised~~]]		[[File:Amstrad-pc1512-ad.jpg\|thumb\|right\|300px\|Amstrad PC1512 advertisement]]

	[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]		[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]

← Older revision		Revision as of 13:22, 11 May 2025
Line 1:		Line 1:
	[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]		[[Image:Amstrad pc1512-2.jpg\|thumb\|right\|300px\|The '''Amstrad PC1512''' - The first PC by Amstrad]]

			[[File:Amstrad-pc1512-ad.jpg\|thumb\|right\|300px\|Amstrad PC1512 advertised]]

	[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]		[[Image:Amstrad PC20.jpg\|thumb\|right\|300px\|The '''Amstrad PC20''' - An attempt to market the PC as a home computer]]