ARA Video Digitizer - Revision history

MacDeath at 18:07, 19 December 2010

2010-12-19T18:07:14Z

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	~~[[Category:Hardware]]~~[[Category:Peripherals]][[Category:Graphic]]		[[Category:Peripherals]][[Category:Graphic]]

MacDeath at 00:16, 17 December 2010

2010-12-17T00:16:12Z

← Older revision		Revision as of 00:16, 17 December 2010
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	* [[VIDI digitizer]] - another video digitizer (Rombo Productions)		* [[VIDI digitizer]] - another video digitizer (Rombo Productions)


			[[Category:Hardware]][[Category:Peripherals]][[Category:Graphic]]

Nocash at 21:08, 11 August 2010

2010-08-11T21:08:26Z

← Older revision		Revision as of 21:08, 11 August 2010
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	A video digitizer made by Philippe Borg in 1987, for a french company ~~called~~ Jagot & Leon. The french name of the hardware is ''Digizaliseur Ara'' (seen on sticker), or ''Ara Digitaliseur d'images video'' (seen on screenshot).		A video digitizer made by Philippe Borg in 1987, for the french company [[Jagot & Leon]]. The french name of the hardware is ''Digizaliseur Ara'' (seen on sticker), or ''Ara Digitaliseur d'images video'' (seen on screenshot).

	ARA is said to be simply referring to the colourful parrot with same name (rather than being an abbreviation for something like analog recording apparatus or so).		ARA is said to be simply referring to the colourful parrot with same name (rather than being an abbreviation for something like analog recording apparatus or so).

Nocash: /* 10bit Config Value */

2010-05-08T13:29:37Z

10bit Config Value

← Older revision		Revision as of 13:29, 8 May 2010
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	=== 10bit Config Value ===		=== 10bit Config Value ===
	The Z80's 8bit databus doesn't allow to write 10bit values. The ARA is using a rather strange solution to overcome that problem. The mechanism to set Config=N is:		The Z80's 8bit databus doesn't allow to write 10bit values. The ARA is using a rather strange solution to overcome that problem.
			The mechanism to set Config=N is:
	OUT [F9F5h],garbage, FOR I=1 to N, OUT [FAF5h],garbage, NEXT I		OUT [F9F5h],garbage, FOR I=1 to N, OUT [FAF5h],garbage, NEXT I
	Whereas, the separate bits in "N" are:		Whereas, the separate bits in "N" are:
	0-1 Contrast		0-1 Contrast
	2-5 Brightness		2-5 Brightness

Nocash: /* Technical */

2010-05-08T13:29:04Z

Technical

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	The hardware consists of an A/D converter, and bunch of logic chips. It does also includes two 8K SRAM chips, used as 16K capture buffer (the image is captured to that buffer in realtime, and can then be read by software at slower speed).		The hardware consists of an A/D converter, and bunch of logic chips. It does also includes two 8K SRAM chips, used as 16K capture buffer (the image is captured to that buffer in realtime, and can then be read by software at slower speed).

	The device connects to SCART connector on ~~TV Set~~ (or ~~Video Recorder~~ or other picture source). There seem to be no attempts to decode SECAM color informations, ie. only luminance (brightness) seems to be supported. Luminance should be same in all countries, so it should also work with PAL/NTSC.		The device connects to SCART connector on Video Recorder (or camcorder or other picture source). There seem to be no attempts to decode SECAM color informations, ie. only luminance (brightness) seems to be supported. Luminance should be same in all countries, so it should also work with PAL/NTSC.

	Two capture formats are supported: 320x200x4 and 160x200x16. Of which, in practice, the software supports only max 8 colors, not 16 colors (nethertheless, the actual hardware might, or might not support 16 colors, and it's just the software ignoring their LSBs; the CPC's 27-color palette isn't suitable for displaying 16 "grayscales").		Two capture formats are supported: 320x200x4 and 160x200x16. Of which, in practice, the software supports only max 8 colors, not 16 colors (nethertheless, the actual hardware might, or might not support 16 colors, and it's just the software ignoring their LSBs; the CPC's 27-color palette isn't suitable for displaying 16 "grayscales").

			The captured data bytes are having the bits arranged differently as CPC's VRAM. For details, see the mode 0 and mode 1 translation tables in the disassembly.

	=== I/O Port Summary ===		=== I/O Port Summary ===

Nocash: /* Technical */

2010-05-08T13:25:13Z

Technical

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	=== Dotclock ===		=== Dotclock ===
	The dotclock (horizontal resolution) is unknown. For a CPC-like aspect ratio, it ''should'' be 4MHz (for 320 pixel resolution), which could be obtained from expansion port. However, the digitizer includes it's own crystal (the photo isn't clear there, it ''looks'' like 5MHz or 6MHz) (but more probably it's something like 16MHz, the leading "1" being invisible on the photo, 16MHz would be reasonable for splitting a 4MHz dotclock into 4 steps).		The dotclock (horizontal resolution) is unknown. For a CPC-like aspect ratio, it ''should'' be 4MHz (for 320 pixel resolution), which could be obtained from expansion port. However, the digitizer includes it's own crystal (the photo isn't clear there, it ''looks'' like 5MHz or 6MHz) (but more probably it's something like 16MHz, the leading "1" being invisible on the photo, 16MHz would be reasonable for splitting a 4MHz dotclock into 4 steps).

			=== Disassembly ===

			* [[Media:Ara video digitizer disassembled.txt]] - disassembled ARA.BIN scanning function

	== Pictures ==		== Pictures ==

Nocash: /* Download */

2010-05-05T12:56:24Z

Download

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	Caution: The software includes some french-cuisine-slang expressions which may confuse english users. For example, "ENTREE : DIGITIZE" means "begin with pressing D for digitize". Namely, it does NOT mean "to press ENTER for digitize".		Caution: The software includes some french-cuisine-slang expressions which may confuse english users. For example, "ENTREE : DIGITIZE" means "begin with pressing D for digitize". Namely, it does NOT mean "to press ENTER for digitize".

			== See also ==

			* [[VIDI digitizer]] - another video digitizer (Rombo Productions)

Nocash: /* Download */

2010-05-03T23:18:48Z

Download

← Older revision		Revision as of 23:18, 3 May 2010
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	* [[Media:ARA Digitaliseur Video Disc.zip]] (dsk)		* [[Media:ARA Digitaliseur Video Disc.zip]] (dsk)

			Caution: The software includes some french-cuisine-slang expressions which may confuse english users. For example, "ENTREE : DIGITIZE" means "begin with pressing D for digitize". Namely, it does NOT mean "to press ENTER for digitize".

Nocash: /* Main Menu */

2010-05-03T23:15:43Z

Main Menu

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	=== Main Menu ===		=== Main Menu ===

	To get here, press "E" in Boot menu (or ENTER at Slideshow Prompt). Available options are then... well, they are strange: The cuisine related words, ''entree, hor's d'oeuvres, ~~specialies~~ du chef, and dessert'' are jokes - ignore them. The actual options are:		To get here, press "E" in Boot menu (or ENTER at Slideshow Prompt). Available options are then... well, they are strange: The french cuisine related words, ''entree, hor's d'oeuvres, specialites du chef, and dessert'' are jokes - ignore them. The actual options are:
	D = Digitize		D = Digitize
	P = Paint (allows to edit colour scheme)		P = Paint (allows to edit colour scheme)

Nocash: /* 10bit Config Value */

2010-05-03T23:12:23Z

10bit Config Value

← Older revision		Revision as of 23:12, 3 May 2010
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	The Z80's 8bit databus doesn't allow to write 10bit values. The ARA is using a rather strange solution to overcome that problem. The mechanism to set Config=N is:		The Z80's 8bit databus doesn't allow to write 10bit values. The ARA is using a rather strange solution to overcome that problem. The mechanism to set Config=N is:
	OUT [F9F5h],garbage, FOR I=1 to N, OUT [FAF5h],garbage, NEXT I		OUT [F9F5h],garbage, FOR I=1 to N, OUT [FAF5h],garbage, NEXT I
	~~The~~ separate bits in "N" are:		Whereas, the separate bits in "N" are:
	0-1 Contrast		0-1 Contrast
	2-5 Brightness		2-5 Brightness