Tilemap Control Register - Revision history

Ped7g: more explicit description of palette offset

2020-05-13T11:11:34Z

more explicit description of palette offset

← Older revision		Revision as of 12:11, 13 May 2020
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	Bit 4 selects one of two tilemap palettes used for final colour lookup.		Bit 4 selects one of two tilemap palettes used for final colour lookup.

	Bit 3 enables "text mode" where the tile-graphic is defined as 1-bit B&W bitmap (same as UDG = User Defined Graphic characters on original ZX Spectrum) => one tile needs only 8 bytes to define graphics. The tile-map data are also interpreted differently, the associated flag byte is 7:1 split, the bottom bit 0 being still "ULA over Tilemap" or "ninth bit of tile number", but the top 7 bits are extended palette offset. The transparency is then checked against the {{NextRegNo\|$14}} colour (after the colour lookup in the palette), not against the four bit Tilemap transparency colour-index.		Bit 3 enables "text mode" where the tile-graphic is defined as 1-bit B&W bitmap (same as UDG = User Defined Graphic characters on original ZX Spectrum) => one tile needs only 8 bytes to define graphics. The tile-map data are also interpreted differently, the associated flag byte is 7:1 split, the bottom bit 0 being still "ULA over Tilemap" or "ninth bit of tile number", but the top 7 bits are extended palette offset (copied as top 7 bits of palette index, the eight bottom bit is the pixel value). The transparency is then checked against the {{NextRegNo\|$14}} colour (after the colour lookup in the palette), not against the four bit Tilemap transparency colour-index.

	Bit 1 enables the 512-tile-mode when the tile attribute (either global in {{NextRegNo\|$6C}} or per tile in map data) contains ninth bit of tile-id value. In this mode the tiles are drawn under ULA pixels, unless bit 0 is used to force whole Tilemap over ULA.		Bit 1 enables the 512-tile-mode when the tile attribute (either global in {{NextRegNo\|$6C}} or per tile in map data) contains ninth bit of tile-id value. In this mode the tiles are drawn under ULA pixels, unless bit 0 is used to force whole Tilemap over ULA.

	Bit 0 can enforce Tilemap over ULA either in 512-tile-mode, or even override the per-tile bit selector from tile attributes. If zero, the Tilemap priority is either decided by attribute bit or in 512-tile-mode it is under ULA.		Bit 0 can enforce Tilemap over ULA either in 512-tile-mode, or even override the per-tile bit selector from tile attributes. If zero, the Tilemap priority is either decided by attribute bit or in 512-tile-mode it is under ULA.

Ped7g: core 3.0 changes/refresh

2019-11-12T07:16:59Z

core 3.0 changes/refresh

← Older revision		Revision as of 08:16, 12 November 2019
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	\| 4 \|\| palette select (0 = first Tilemap palette, 1 = second)		\| 4 \|\| palette select (0 = first Tilemap palette, 1 = second)
	\|-		\|-
	\| 3 \|\| ~~(core 3.0)~~ enable "text mode"		\| 3 \|\| enable "text mode"
	\|-		\|-
	\| 2 \|\| Reserved, must be 0		\| 2 \|\| Reserved, must be 0
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	Bits 7 & 6 enable the tilemap and select resolution.		Bits 7 & 6 enable the tilemap and select resolution.

	Bit 5 changes the structure of the tilemap so that it contains only 8-bit tilemap-id entries instead of 16-bit tilemap-id ~~and~~ tile-attribute entries.		Bit 5 changes the structure of the tilemap so that it contains only 8-bit tilemap-id entries instead of 16-bit tilemap-id plus tile-attribute entries.

	If 8-bit tilemap is selected, the tilemap contains only tile numbers and the attributes are taken from {{NextRegNo\|$6C}}.		If 8-bit tilemap is selected, the tilemap contains only tile numbers and the attributes are taken from {{NextRegNo\|$6C}}.
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	Bit 4 selects one of two tilemap palettes used for final colour lookup.		Bit 4 selects one of two tilemap palettes used for final colour lookup.

	Bit 1 enables the ~~512~~-~~tile~~-~~mode when the~~ tile ~~attribute (either global in $6C or per~~ tile in map data~~) contains~~ ninth bit of tile~~-id value~~. ~~In this mode~~ the ~~tiles are drawn under ULA pixels~~, ~~unless~~ bit ~~0 is used to force whole tilemap over ULA~~.		Bit 3 enables "text mode" where the tile-graphic is defined as 1-bit B&W bitmap (same as UDG = User Defined Graphic characters on original ZX Spectrum) => one tile needs only 8 bytes to define graphics. The tile-map data are also interpreted differently, the associated flag byte is 7:1 split, the bottom bit 0 being still "ULA over Tilemap" or "ninth bit of tile number", but the top 7 bits are extended palette offset. The transparency is then checked against the {{NextRegNo\|$14}} colour (after the colour lookup in the palette), not against the four bit Tilemap transparency colour-index.

	Bit ~~0 can enforce tilemap over ULA either in~~ 512-tile-mode, or ~~even override the~~ per-tile bit ~~selector from~~ tile ~~attributes~~. ~~If zero~~, ~~the tilemap priority is either decided by attribute~~ bit ~~or in 512-tile-mode it~~ is ~~under~~ ULA.		Bit 1 enables the 512-tile-mode when the tile attribute (either global in {{NextRegNo\|$6C}} or per tile in map data) contains ninth bit of tile-id value. In this mode the tiles are drawn under ULA pixels, unless bit 0 is used to force whole Tilemap over ULA.

	~~'''NEW~~ in ~~core 3.0:'''~~		Bit 0 can enforce Tilemap over ULA either in 512-tile-mode, or even override the per-tile bit selector from tile attributes. If zero, the Tilemap priority is either decided by attribute bit or in 512-tile-mode it is under ULA.

	~~Bit 3 enables "text~~ mode~~" where~~ the tile~~-graphic is defined as 1-~~bit ~~B&W bitmap (same as UDG = User Defined Graphic characters on original ZX Spectrum) => one~~ tile ~~needs only 8 bytes to define graphics~~. ~~The tile-map data are also interpreted differently~~, the ~~associated flag byte~~ is ~~7:1 split, the bottom~~ bit ~~0 being still "ULA over tm"~~ or ~~"ninth bit of~~ tile ~~number", but the top 7 bits are extended palette offset. The transparency~~ is ~~then checked against the global transparency colour (after the colour lookup in the palette), not against the four bit tilemap transparency colour-index~~.

Ped7g: core 3.0 changes

2019-10-03T20:56:55Z

core 3.0 changes

← Older revision		Revision as of 21:56, 3 October 2019
Line 16:		Line 16:
	\| 4 \|\| palette select (0 = first Tilemap palette, 1 = second)		\| 4 \|\| palette select (0 = first Tilemap palette, 1 = second)
	\|-		\|-
	\| 3-2 \|\| Reserved, must be 0		\| 3 \|\| (core 3.0) enable "text mode"
			\|-
			\| 2 \|\| Reserved, must be 0
	\|-		\|-
	\| 1 \|\| 1 to activate 512 tile mode (bit 0 of tile attribute is ninth bit of tile-id)<br />		\| 1 \|\| 1 to activate 512 tile mode (bit 0 of tile attribute is ninth bit of tile-id)<br />
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	Bit 0 can enforce tilemap over ULA either in 512-tile-mode, or even override the per-tile bit selector from tile attributes. If zero, the tilemap priority is either decided by attribute bit or in 512-tile-mode it is under ULA.		Bit 0 can enforce tilemap over ULA either in 512-tile-mode, or even override the per-tile bit selector from tile attributes. If zero, the tilemap priority is either decided by attribute bit or in 512-tile-mode it is under ULA.

			'''NEW in core 3.0:'''

			Bit 3 enables "text mode" where the tile-graphic is defined as 1-bit B&W bitmap (same as UDG = User Defined Graphic characters on original ZX Spectrum) => one tile needs only 8 bytes to define graphics. The tile-map data are also interpreted differently, the associated flag byte is 7:1 split, the bottom bit 0 being still "ULA over tm" or "ninth bit of tile number", but the top 7 bits are extended palette offset. The transparency is then checked against the global transparency colour (after the colour lookup in the palette), not against the four bit tilemap transparency colour-index.

Ped7g: cross-linking with main Tilemap article

2019-05-23T05:43:41Z

cross-linking with main Tilemap article

← Older revision		Revision as of 06:43, 23 May 2019
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	\|Readable=Yes		\|Readable=Yes
	\|Writable=Yes		\|Writable=Yes
	\|ShortDesc=Controls Tilemap mode.		\|ShortDesc=Controls [[Tilemap]] mode.
	}}		}}
	{\| class="wikitable"		{\| class="wikitable"

Specnext: 2 revisions imported

2019-04-14T10:00:22Z

2 revisions imported

← Older revision	Revision as of 11:00, 14 April 2019
(No difference)

wiki>Ped7g: Core 2.00.27 changes.

2019-02-13T22:38:10Z

Core 2.00.27 changes.

← Older revision		Revision as of 23:38, 13 February 2019
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	\| 4 \|\| palette select (0 = first Tilemap palette, 1 = second)		\| 4 \|\| palette select (0 = first Tilemap palette, 1 = second)
	\|-		\|-
	\| 3-0 \|\| Reserved, must be 0		\| 3-2 \|\| Reserved, must be 0
			\|-
			\| 1 \|\| 1 to activate 512 tile mode (bit 0 of tile attribute is ninth bit of tile-id)<br />
			0 to use bit 0 of tile attribute as "ULA over tilemap" per-tile-selector
			\|-
			\| 0 \|\| 1 to enforce "tilemap over ULA" layer priority
	\|}		\|}

Line 26:		Line 31:

	Bit 4 selects one of two tilemap palettes used for final colour lookup.		Bit 4 selects one of two tilemap palettes used for final colour lookup.

			Bit 1 enables the 512-tile-mode when the tile attribute (either global in $6C or per tile in map data) contains ninth bit of tile-id value. In this mode the tiles are drawn under ULA pixels, unless bit 0 is used to force whole tilemap over ULA.

			Bit 0 can enforce tilemap over ULA either in 512-tile-mode, or even override the per-tile bit selector from tile attributes. If zero, the tilemap priority is either decided by attribute bit or in 512-tile-mode it is under ULA.

wiki>Ped7g: Core 2.00.26 changes

2019-01-31T19:41:40Z

Core 2.00.26 changes

New page

{{NextRegister
|Number=$6B
|Readable=Yes
|Writable=Yes
|ShortDesc=Controls Tilemap mode.
}}
{| class="wikitable"
! Bit !! Function
|-
| 7 || 1 to enable the tilemap
|-
| 6 || 0 for 40x32, 1 for 80x32
|-
| 5 || 1 to eliminate the attribute entry in the tilemap
|-
| 4 || palette select (0 = first Tilemap palette, 1 = second)
|-
| 3-0 || Reserved, must be 0
|}

Bits 7 & 6 enable the tilemap and select resolution.

Bit 5 changes the structure of the tilemap so that it contains only 8-bit tilemap-id entries instead of 16-bit tilemap-id and tile-attribute entries.

If 8-bit tilemap is selected, the tilemap contains only tile numbers and the attributes are taken from {{NextRegNo|$6C}}.

Bit 4 selects one of two tilemap palettes used for final colour lookup.