Super MegaZeux - Revision history

Asiekierka: /* Compatibility */

2024-03-20T19:13:00Z

Compatibility

@@ Line 358: / Line 358: @@
   | No
   | Lachesis
+  |
   |}
@@ Line 506: / Line 515: @@
   | [https://github.com/joncampbell123/dosbox-x/issues/4764#issuecomment-1918121416 Jon Campbell]
   | Doubles left pixel.
   |-
   | S3 Savage 2000

Asiekierka: /* Compatibility */

2024-03-20T17:50:33Z

Compatibility

@@ Line 241: / Line 241: @@
   | Yes
   | [https://tenforward.social/@kepstin/112034114772189201 kepstin]
+  |
   |-
@@ Line 517: / Line 526: @@
   | smzxtest
   | [https://misskey.resonite.love/notes/9qwod5kpd2 GreaseMonkey]
-  | No doubling?
+  | No doubling
   |-
   | SiS 530

Asiekierka: /* Incompatible hardware */

2024-03-20T17:07:59Z

Incompatible hardware

← Older revision		Revision as of 17:07, 20 March 2024
Line 496:		Line 496:
	\| 2.70		\| 2.70
	\| [https://github.com/joncampbell123/dosbox-x/issues/4764#issuecomment-1918121416 Jon Campbell]		\| [https://github.com/joncampbell123/dosbox-x/issues/4764#issuecomment-1918121416 Jon Campbell]
			\| Doubles left pixel.
			\|-
			\| S3 Savage 2000
			\| 1999
			\| -
			\| smzxtest
			\| [https://mastodon.social/@Vyothric/112129105464362419 Vyothric]
	\| Doubles left pixel.		\| Doubles left pixel.
	\|-		\|-

Asiekierka: /* Compatibility */

2024-03-20T17:05:46Z

Compatibility

@@ Line 391: / Line 391: @@
   | smzxtest
   | [https://mas.to/@dukeboitans/112100827940981639 dukeboitans]
   | Doubles right pixel.
   |-
@@ Line 426: / Line 433: @@
   | smzxtest
   | Lachesis
   | Doubles left pixel.
   |-

Lachesis: /* Variations */ Correct combination spacings.

2024-03-17T01:33:20Z

Variations: Correct combination spacings.

← Older revision		Revision as of 01:33, 17 March 2024
Line 155:		Line 155:
	x 4 4 f 4 f f 4 f y		x 4 4 f 4 f f 4 f y

	x4 4f 4f f4 fy		x4 4f 4f f4 fy

	Another complication is that 9-pixel wide text modes will switch combination "parity" every other character (extra pixels in brackets):		Another complication is that 9-pixel wide text modes will switch combination "parity" every other character (extra pixels in brackets):
Line 161:		Line 161:
	4 4 f 4 f f 4 f [4] 4 4 f 4 f f 4 f [4]		4 4 f 4 f f 4 f [4] 4 4 f 4 f f 4 f [4]

	44 f4 ff 4f [4]4 4f 4f f4 f[4]		44 f4 ff 4f [4]4 4f 4f f4 f[4]

	Typically laptop adapters that perform forced 9-pixel or wider text mode scaling can have this behavior disabled with an Fn+function key combination.		Typically laptop adapters that perform forced 9-pixel or wider text mode scaling can have this behavior disabled with an Fn+function key combination.

Lachesis: Add "Hardware Details" section.

2024-03-17T01:30:02Z

Add "Hardware Details" section.

← Older revision		Revision as of 01:30, 17 March 2024
Line 130:		Line 130:

	As of MegaZeux 2.90, the color mappings of all 256 subpalettes in SMZX mode 3 can be customized either by using the '''SMZX_IDXx,y''' counter or by reassigning them in the SMZX [[palette editor]].		As of MegaZeux 2.90, the color mappings of all 256 subpalettes in SMZX mode 3 can be customized either by using the '''SMZX_IDXx,y''' counter or by reassigning them in the SMZX [[palette editor]].

			==Hardware details==

			Super MegaZeux modes 1 and 2 are derived from a quirk of VGA (Video Graphics Array) compatible video adapters. In the video adapters that support SMZX, enabling the 8-bit color flag (0x40) of the Attribute Mode Control register (port 0x3C0 register 0x10) will combine two adjacent 4-bit EGA palette indices into a single 8-bit VGA palette index. This flag is intended for mode 13h only; enabling this in 14p text mode is undefined behavior. Most graphics chips do not render this 8-bit color text mode hack "correctly".

			Example: given the text mode character byte 0x2d:

			░░▓░▓▓░▓

			With the palette 0x4F, this text mode byte is typically expanded to 4-bit color indices (hex):

			4 4 f 4 f f 4 f

			When the 8-bit color flag is enabled, two adjacent 4-bit indices are combined in a big endian manner to create a single 8-bit index (hex):

			44 f4 ff 4f

			These 8-bit indices are used to index the VGA palette. This is a "normal" SMZX mode implementation.

			===Variations===

			When combined with horizontal pixel panning (port 0x3C0 register 0x13), this combination usually behaves unexpectedly. For example, with a pixel panning value of 0x01 (shift left one pixel), and values ''x'' and ''y'' as 4-bit colors inherited from the neighboring characters, this same character combines into different colors:

			x 4 4 f 4 f f 4 f y

			x4 4f 4f f4 fy

			Another complication is that 9-pixel wide text modes will switch combination "parity" every other character (extra pixels in brackets):

			4 4 f 4 f f 4 f [4] 4 4 f 4 f f 4 f [4]

			44 f4 ff 4f [4]4 4f 4f f4 f[4]

			Typically laptop adapters that perform forced 9-pixel or wider text mode scaling can have this behavior disabled with an Fn+function key combination.

			===Vendors===

			Chips & Technologies (all models that have been tested), NVIDIA adapters (from between some time in the '90s and some time in the late '00s), and the later VIA S3 Graphics "Chrome" adapters implement "normal" SMZX text mode as described above. No compatibility hacks are required for these vendors.

			ATI graphics cards (from some time in the mid '90s until 2006) shift their text mode to the right by one pixel and seem to combine the 4-bit colors in a ''little'' endian manner, i.e. "4 f" are combined into "f4". To correct this, MegaZeux applies a horizontal pixel panning value of 0x01 and reverses the index nibbles of all SMZX colors when sending them to the VGA.

			''Some'' early Oak Technologies chips seem to combine the 4-bit colors in a little endian manner as well, but without the unusual pixel shift that ATI cards had. This needs more testing. MegaZeux currently has no method of detecting this.

			See the compatibility tables below for more info.

	==Compatibility==		==Compatibility==

Lachesis: /* How It Works */ Clarify and fix typos.

2024-03-16T20:52:25Z

How It Works: Clarify and fix typos.

← Older revision		Revision as of 20:52, 16 March 2024
Line 13:		Line 13:
	SMZX mode can be accessed by setting the '''SMZX_MODE''' counter to 1, 2, or 3. In the editor, the current SMZX mode can be changed with the Select Screen Mode dialog (F11).		SMZX mode can be accessed by setting the '''SMZX_MODE''' counter to 1, 2, or 3. In the editor, the current SMZX mode can be changed with the Select Screen Mode dialog (F11).

	==How ~~It Works~~==		==How it works==
	SMZX Mode halves the horizontal screen resolution in favor of adding two colors per character, effectively making a color palette of 256 unique colors.		SMZX Mode halves the horizontal screen resolution in favor of adding two colors per character, effectively making a color palette of 256 unique colors.

	Each "pixel" in SMZX ~~can be either color~~ I ~~(represented in MZX mode as two~~ 'off' ~~pixels), color~~ II ('on' ~~and~~ 'off'~~), color~~ III ('off' ~~and~~ 'on'~~) ad color~~ IV ~~(both~~ 'on').		Each "pixel" in SMZX is derived from a horizontally adjacent pair of text mode pixels in the following manner:
			{\|class="wikitable"
			\|+
			!Color
			!Left pixel
			!Right pixel
			\|-
			\|Color I
			\|'''off'''
			\|'''off'''
			\|-
			\|Color II
			\|'''on'''
			\|'''off'''
			\|-
			\|Color III
			\|'''off'''
			\|'''on'''
			\|-
			\|Color IV
			\|'''on'''
			\|'''on'''
			\|}

			If colors II and III seem backwards to experienced programmers, it is not a mistake; this is how the original DOS versions defined these colors.


Line 47:		Line 71:

	===SMZX Mode 2===		===SMZX Mode 2===
	SMZX mode 2 was the first to allow ~~4 colors per character that the~~ user ~~had full~~ control over. It ~~uses the same color matrix as~~ SMZX mode 1, but instead of ~~automatically~~ generating the new colors ~~off of~~ a ~~standard~~ 16 color palette, it ~~references a user-defined~~ 256 color ~~palette~~ to ~~find~~ the ~~colors~~. All colors are defined in pairs of 2 hex digits, represented below by 0xNN. Given the same example palette as before, c4F, the colors are referenced as such:		SMZX mode 2 was the first mode to allow full user control over the 256 color palette. It is internally identical to SMZX mode 1, but instead of generating the new colors from a user-defined 16 color palette, it allows direct reading and writing of all 256 colors either through the '''set color # to # # #''' command or with the counters '''SMZX_Rn''', '''SMZX_Gn''', and '''SMZX_Bn'''.

			All colors are defined in pairs of 2 hex digits, represented below by 0xNN. Given the same example palette as before, c4F, the colors are referenced as such:

	{\|class="wikitable"		{\|class="wikitable"
Line 64:		Line 90:
	\|-		\|-
	\|Color III		\|Color III
	\|Uses the BG for the most significant hex digit and the FG ~~fore~~ the least significant hex digit		\|Uses the BG for the most significant hex digit and the FG for the least significant hex digit
	\|Color #0x4F (79 decimal)		\|Color #0x4F (79 decimal)
	\|-		\|-
Line 72:		Line 98:
	\|}		\|}

	~~If the color indexes for~~ colors II and III ~~seem~~ backwards to ~~experienced programmers~~, ~~it is not a mistake;~~ this ~~is how they actually are~~.		(Note that colors II and III are backwards here to compensate for the backwards definitions of colors II and III from the character data. In practice, this won't matter to most users.)


	===SMZX Mode 3===		===SMZX Mode 3===
	SMZX mode 3, which was added with the SDL port, uses a palette of 256 ~~separate~~ colors as opposed to 16 ~~foreground and 16 background~~ colors ~~(each color, in hex, is a 2-digit pair consisting~~ of ~~the background color~~ and the ~~foreground color). Characters can access these~~ as ~~following~~:		SMZX mode 3, which was added with the SDL port, uses a palette of 256 completely independent colors as opposed to the effective 16 "base" colors of modes 1 and 2. By default, the colors for each subpalette cXX are defined as:

	{\|class="wikitable"		{\|class="wikitable"
Line 101:		Line 127:
	\|}		\|}

	~~hence yielding a set of 64 unique color palettes. The colors~~ wrap around, so ~~a character set to color~~ 255 ~~(0xFF) will use color~~ 0 ~~for color II, etc~~.		Subpalettes 253 through 255 "wrap around" the palette, so e.g. subpalette 253 will contain colors 253, 254, 255, and 0.

	As of MegaZeux 2.90, the color mappings of all 256 subpalettes in SMZX mode 3 can be customized either by using the '''SMZX_IDXx,y''' counter or by reassigning them in the SMZX [[palette editor]].		As of MegaZeux 2.90, the color mappings of all 256 subpalettes in SMZX mode 3 can be customized either by using the '''SMZX_IDXx,y''' counter or by reassigning them in the SMZX [[palette editor]].

Asiekierka: /* Incompatible hardware */

2024-03-15T20:32:21Z

Incompatible hardware

← Older revision		Revision as of 20:32, 15 March 2024
Line 425:		Line 425:
	\| HP Brio 8314		\| HP Brio 8314
	\| smzxtest		\| smzxtest
	\| GreaseMonkey		\| [https://misskey.resonite.love/notes/9qwod5kpd2 GreaseMonkey]
	\| No doubling.		\| No doubling?
	\|-		\|-
	\| SiS 530		\| SiS 530

Asiekierka: /* Incompatible hardware */

2024-03-15T20:31:27Z

Incompatible hardware

← Older revision		Revision as of 20:31, 15 March 2024
Line 420:		Line 420:
	\| Elig		\| Elig
	\| Doubles left pixel.		\| Doubles left pixel.
			\|-
			\| S3 Trio64V2/DX
			\| 1996
			\| HP Brio 8314
			\| smzxtest
			\| GreaseMonkey
			\| No doubling.
	\|-		\|-
	\| SiS 530		\| SiS 530

Asiekierka: /* Compatibility */

2024-03-15T19:46:46Z

Compatibility

@@ Line 315: / Line 315: @@
   | Lachesis
   | No doubling. (ATI detected)
   |-
   | Cirrus Logic CL-GD5440
@@ Line 420: / Line 427: @@
   | [https://mastodon.social/@indigoparadox/112032243607415455 indigoparadox]
   | Doubles left pixel.
   |}