V9938 Video Data Processor - Revision history

Stefan Haubenthal: Categories

2025-02-02T12:32:29Z

Mizapf: /* Video modes */

2019-06-12T15:44:21Z

Video modes

← Older revision		Revision as of 15:44, 12 June 2019
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	The V9938 was built with downward compatibility in mind; the first 8 video registers are used in the same way as those in the TMS9928. It fully implements the TMS9928 modes and some more in addition.		The V9938 was built with downward compatibility in mind; the first 8 video registers are used in the same way as those in the TMS9928. It fully implements the TMS9928 modes and some more in addition.

	The Text 2 mode is a 80 char/line mode which allows for marking positions as "blinking" with a selectable blink rate, including 0. In that case, the locations are highlighted. You can set a foreground and background color for all of the marked positions on the screen, thus ~~delivering~~ 2 foreground and 2 background colors.		The Text 2 mode is a 80 char/line mode which allows for marking positions as "blinking" with a selectable blink rate, including 0. In that case, the locations are highlighted. You can set a foreground and background color for all of the marked positions on the screen, thus allowing for 2 foreground and 2 background colors.

	Graphic 7 mode is the only mode without palette colors. In this mode, pixels are shown in a color composed of GGGRRRBB, that is, with the first three bits representing the green component, the next three bits standing for red, and the right two ones for blue.		Graphic 7 mode is the only mode without palette colors. In this mode, pixels are shown in a color composed of GGGRRRBB, that is, with the first three bits representing the green component, the next three bits standing for red, and the right two ones for blue.

Mizapf: /* Video modes */

2019-06-12T15:43:56Z

Video modes

← Older revision		Revision as of 15:43, 12 June 2019
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	The Text 2 mode is a 80 char/line mode which allows for marking positions as "blinking" with a selectable blink rate, including 0. In that case, the locations are highlighted. You can set a foreground and background color for all of the marked positions on the screen, thus delivering 2 foreground and 2 background colors.		The Text 2 mode is a 80 char/line mode which allows for marking positions as "blinking" with a selectable blink rate, including 0. In that case, the locations are highlighted. You can set a foreground and background color for all of the marked positions on the screen, thus delivering 2 foreground and 2 background colors.

	Graphic 7 mode is the only mode without palette colors. In this mode, pixels are shown in a color composed of GGGRRRBB, that is, with the first three bits representing the green ~~components~~ and ~~so on~~.		Graphic 7 mode is the only mode without palette colors. In this mode, pixels are shown in a color composed of GGGRRRBB, that is, with the first three bits representing the green component, the next three bits standing for red, and the right two ones for blue.

	{\| class="plain"		{\| class="plain"

Mizapf: /* Video modes */

2019-06-12T15:42:26Z

Video modes

← Older revision		Revision as of 15:42, 12 June 2019
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	== Video modes ==		== Video modes ==

			The V9938 was built with downward compatibility in mind; the first 8 video registers are used in the same way as those in the TMS9928. It fully implements the TMS9928 modes and some more in addition.

			The Text 2 mode is a 80 char/line mode which allows for marking positions as "blinking" with a selectable blink rate, including 0. In that case, the locations are highlighted. You can set a foreground and background color for all of the marked positions on the screen, thus delivering 2 foreground and 2 background colors.

			Graphic 7 mode is the only mode without palette colors. In this mode, pixels are shown in a color composed of GGGRRRBB, that is, with the first three bits representing the green components and so on.

	{\| class="plain"		{\| class="plain"
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	\|-		\|-
	\| Text 2		\| Text 2
	\| Text-only mode		\| Text-only mode with blinking
	\| 80x25		\| 80x25
	\| -		\| -

Mizapf: /* Video modes */

2019-06-12T15:36:00Z

Video modes

← Older revision		Revision as of 15:36, 12 June 2019
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	! Description		! Description
	! Positions		! Positions
			! Sprite mode
			! Colors
	! Corresponding TMS9928 mode		! Corresponding TMS9928 mode
	\|-		\|-
	\| Text 1		\| Text 1
	\| ~~Two~~-~~color text~~ mode		\| Text-only mode
	\| ~~40x25~~		\| 40x24
			\| -
			\| 2 of 512
	\| Text		\| Text
	\|-		\|-
	\| Text 2		\| Text 2
	\| ~~Two~~-~~color text~~ mode ~~with another two-color blink/highlight~~		\| Text-only mode
	\| 80x25		\| 80x25
			\| -
			\| 4 of 512
	\| -		\| -
	\|-		\|-
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	\| 4x4 block color graphics		\| 4x4 block color graphics
	\| 64x48		\| 64x48
			\| 1
			\| 16 of 512
	\| Multicolor		\| Multicolor
	\|-		\|-
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	\| Character-oriented graphics		\| Character-oriented graphics
	\| 32x24		\| 32x24
			\| 1
			\| 16 of 512
	\| Graphics		\| Graphics
	\|-		\|-
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	\| Character-oriented graphics, full screen		\| Character-oriented graphics, full screen
	\| 32x24		\| 32x24
			\| 1
			\| 16 of 512
	\| Bitmap		\| Bitmap
	\|-		\|-
	\| Graphic 3		\| Graphic 3
	\| Character-oriented graphics, full screen~~, sprite mode 2~~		\| Character-oriented graphics, full screen
	\| 32x24		\| 32x24
			\| 2
			\| 16 of 512
	\| -		\| -
	\|-		\|-
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	\| Pixel-oriented bitmap mode, 16 colors		\| Pixel-oriented bitmap mode, 16 colors
	\| 256x192 (212)		\| 256x192 (212)
			\| 2
			\| 16 of 512
	\| -		\| -
	\|-		\|-
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	\| Pixel-oriented bitmap mode, 4 colors		\| Pixel-oriented bitmap mode, 4 colors
	\| 512x192 (212)		\| 512x192 (212)
			\| 2
			\| 4 of 512
	\| -		\| -
	\|-		\|-
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	\| Pixel-oriented bitmap mode, 16 colors		\| Pixel-oriented bitmap mode, 16 colors
	\| 512x192 (212)		\| 512x192 (212)
			\| 2
			\| 16 of 512
	\| -		\| -
	\|-		\|-
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	\| Pixel-oriented bitmap mode, 256 colors		\| Pixel-oriented bitmap mode, 256 colors
	\| 256x192 (212)		\| 256x192 (212)
			\| 2
			\| 256
	\| -		\| -
	\|}		\|}

Mizapf: /* Benchmarks */

2019-06-11T19:40:48Z

Benchmarks

← Older revision		Revision as of 19:40, 11 June 2019
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	Tests showed that painting a rectangle is faster when there are fewer lines: 30 pixels wide, 60 pixels high is slower than 60 wide and 30 high (about 166 µs).		Tests showed that painting a rectangle is faster when there are fewer lines: 30 pixels wide, 60 pixels high is slower than 60 wide and 30 high (about 166 µs).

	'''~~Graphics~~ 7 mode'''		'''Graphic 7 mode'''

	{\| class="plain"		{\| class="plain"
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	The setup time is a fixed time, independent of the amount of modified pixels on the screen. Maybe it is caused by internal calculations of the VDP, or by some trailing delay. You have to add some more time for your program to set the video registers; this is typically another 100 µs.		The setup time is a fixed time, independent of the amount of modified pixels on the screen. Maybe it is caused by internal calculations of the VDP, or by some trailing delay. You have to add some more time for your program to set the video registers; this is typically another 100 µs.

	'''~~Graphics~~ 6 mode'''		'''Graphic 6 mode'''

	The high-speed operations like HMMV perform at ''double speed''. The reason is that two pixels are processed in a single command invocation. Logical operations only operate on single pixels and thus run at the same speed as in ~~graphics~~ 7.		The high-speed operations like HMMV perform at ''double speed''. The reason is that two pixels are processed in a single command invocation. Logical operations only operate on single pixels and thus run at the same speed as in graphic 7.

	'''Examples''':		'''Examples''':

	The following calculations all refer to ~~graphics~~ 7 mode, and we leave away all setup times. Thus, the required times are lower bounds; it will take longer to perform the action. Also, we assume 192 lines; the V9938 is able to expand this to 212 lines.		The following calculations all refer to graphic 7 mode, and we leave away all setup times. Thus, the required times are lower bounds; it will take longer to perform the action. Also, we assume 192 lines; the V9938 is able to expand this to 212 lines.

	* We'd like to ''paint the whole screen'': There are 192 rows and 256 columns, which means 49152 pixels. Using the HMMV command, we see that this takes t = 2.9 µs * 49152 = 142541 µs = 0.14 secs. Doing that repeatedly, we will achieve less than 8 frames per second.		* We'd like to ''paint the whole screen'': There are 192 rows and 256 columns, which means 49152 pixels. Using the HMMV command, we see that this takes t = 2.9 µs * 49152 = 142541 µs = 0.14 secs. Doing that repeatedly, we will achieve less than 8 frames per second.

Mizapf at 19:40, 11 June 2019

2019-06-11T19:40:09Z

← Older revision		Revision as of 19:40, 11 June 2019
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	! Mode		! Mode
	! Description		! Description
	! ~~Layout~~		! Positions
	! Corresponding TMS9928 mode		! Corresponding TMS9928 mode
	\|-		\|-
	\| Text 1		\| Text 1
	\| Two-color text mode		\| Two-color text mode
	\| 40x25 ~~characters~~		\| 40x25
	\| Text		\| Text
	\|-		\|-
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	\| Multicolor		\| Multicolor
	\| 4x4 block color graphics		\| 4x4 block color graphics
	\| 64x48 ~~positions~~		\| 64x48
	\| Multicolor		\| Multicolor
	\|-		\|-
	\| Graphic 1		\| Graphic 1
	\| Character-oriented graphics		\| Character-oriented graphics
	\| 32x24 ~~positions~~		\| 32x24
	\| Graphics		\| Graphics
	\|-		\|-
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	\|-		\|-
	\| Graphic 4		\| Graphic 4
	\|		\| Pixel-oriented bitmap mode, 16 colors
	\|		\| 256x192 (212)
	\|		\| -
			\|-
			\| Graphic 5
			\| Pixel-oriented bitmap mode, 4 colors
			\| 512x192 (212)
			\| -
			\|-
			\| Graphic 6
			\| Pixel-oriented bitmap mode, 16 colors
			\| 512x192 (212)
			\| -
			\|-
			\| Graphic 7
			\| Pixel-oriented bitmap mode, 256 colors
			\| 256x192 (212)
			\| -
	\|}		\|}

Mizapf: /* Video modes */

2019-06-11T19:18:18Z

Video modes

← Older revision		Revision as of 19:18, 11 June 2019
Line 2:		Line 2:

	== Video modes ==		== Video modes ==

			{\| class="plain"
			! Mode
			! Description
			! Layout
			! Corresponding TMS9928 mode
			\|-
			\| Text 1
			\| Two-color text mode
			\| 40x25 characters
			\| Text
			\|-
			\| Text 2
			\| Two-color text mode with another two-color blink/highlight
			\| 80x25
			\| -
			\|-
			\| Multicolor
			\| 4x4 block color graphics
			\| 64x48 positions
			\| Multicolor
			\|-
			\| Graphic 1
			\| Character-oriented graphics
			\| 32x24 positions
			\| Graphics
			\|-
			\| Graphic 2
			\| Character-oriented graphics, full screen
			\| 32x24
			\| Bitmap
			\|-
			\| Graphic 3
			\| Character-oriented graphics, full screen, sprite mode 2
			\| 32x24
			\| -
			\|-
			\| Graphic 4
			\|
			\|
			\|
			\|}

	== Mouse and Lightpen support ==		== Mouse and Lightpen support ==

Mizapf: /* Benchmarks */

2019-06-11T19:09:02Z

Benchmarks

← Older revision		Revision as of 19:09, 11 June 2019
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	The times for the line operation vary, depending on the angle. Horizontal and vertical lines are fastest, while 45° diagonal lines are slowest. (This is a bit surprising, since on a raster screen, a line always consists of max(dx,dy) pixels.)		The times for the line operation vary, depending on the angle. Horizontal and vertical lines are fastest, while 45° diagonal lines are slowest. (This is a bit surprising, since on a raster screen, a line always consists of max(dx,dy) pixels.)

			Tests showed that painting a rectangle is faster when there are fewer lines: 30 pixels wide, 60 pixels high is slower than 60 wide and 30 high (about 166 µs).

	'''Graphics 7 mode'''		'''Graphics 7 mode'''
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	The setup time is a fixed time, independent of the amount of modified pixels on the screen. Maybe it is caused by internal calculations of the VDP, or by some trailing delay. You have to add some more time for your program to set the video registers; this is typically another 100 µs.		The setup time is a fixed time, independent of the amount of modified pixels on the screen. Maybe it is caused by internal calculations of the VDP, or by some trailing delay. You have to add some more time for your program to set the video registers; this is typically another 100 µs.

			'''Graphics 6 mode'''

			The high-speed operations like HMMV perform at ''double speed''. The reason is that two pixels are processed in a single command invocation. Logical operations only operate on single pixels and thus run at the same speed as in graphics 7.

	'''Examples''':		'''Examples''':

Mizapf: /* Benchmarks */

2019-06-11T16:23:47Z

Benchmarks

← Older revision		Revision as of 16:23, 11 June 2019
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	\|}		\|}

	The setup time is a fixed time, independent of the amount of modified pixels on the screen. Maybe it is caused by internal calculations of the VDP, or by some trailing delay. You have to add some more time for your program to set the video registers; this is typically 100 µs.		The setup time is a fixed time, independent of the amount of modified pixels on the screen. Maybe it is caused by internal calculations of the VDP, or by some trailing delay. You have to add some more time for your program to set the video registers; this is typically another 100 µs.

	'''Examples''':		'''Examples''':

← Older revision		Revision as of 12:32, 2 February 2025
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	If we think about serious game programming, 8 frames per second is pretty disappointing. The line command is certainly useful, and also painting into the rectangles, but mass transfer should be avoided.		If we think about serious game programming, 8 frames per second is pretty disappointing. The line command is certainly useful, and also painting into the rectangles, but mass transfer should be avoided.

			[[Category:Hardware]]
			[[Category:Geneve]]