VICKY II

VICKY II - the graphics engine

"Vicky" is the name of the graphics engine of the C256 Foenix.

"Vicky II" is the upgraded version of the graphic engines that resides in the FMX Version.

The major difference in between VICKY and VICKY II is the external bus @ 32Bits wide. (VICKY is only 16Bits) The access time has been doubled which allow the chipset to have better access time and overall better performance. It also gave enough room to implement larger resolutions with faster GUI block move.

Part Number: CFP9551

It supports:

• 320x240@60FPS Max Resolution @ 256 Colors (1 Byte per pixel)
• 400x300@60FPS Max Resolution @ 256 Colors (1 Byte per pixel)
• 640x480@60FPS Max Resolution @ 256 Colors (1 Byte per pixel)
• 800x600@60FPS Max Resolution @ 256 Colors (1 Byte per pixel) (GUI mode)

• 64 Sprites with a resolution of 32x32 pixels
• 4 layers of Tiles with a resolution of 16x16 pixels for each tile
• Text Mode

During the video layer composition, Vicky has to read 1 line of bitmap (640 pixels), 1 line of tiles for each layer (4x 640 pixels) and all the lines that are part of the 64 Sprites (worst case scenario 32 lines of 32 pixels), that are displayed on that line. Then a composition and priority encoding are done. In order to establish a priority, in other words, to know which pixel will be in front, Vicky needs to store 10 lines of 640 pixels then scan the lot and determine which one will be displayed.

640 + 640 + 640 + 640 + 640 + (32 * 32) = 4224 Pixels are to be read during a single line interval. The pixel rate is 200Mbytes/sec, 5ns, so the overall operation takes 21.12us, without calculating the overhead in the FPGA to go from one process to the other.

The pixel index value $00 is always transparent, regardless if it's bitmap, tile or sprite. The respective values of the first 4 bytes represented in the LUT are thus always ignored.

Despite the fact that there is an ALPHA value in the LUT, it is not supported/used at all.

The picture below shows how the graphics layers are arranged:

Vicky Gloabl Memory Map:

Start Address	Stop Address	Register Description	Additional Info
$AF:0000	$AF:0000	MASTER_CTRL_REG_L	Vicky Master Control Registers
$AF:0001	$AF:0001	MASTER_CTRL_REG_H
$AF:0002	$AF:0002	GAMMA_CTRL_REG
$AF:0003	$AF:0003	VKY_RESERVED_01
$AF:0004	$AF:0004	BORDER_CTRL_REG	Border Control Registers
$AF:0005	$AF:0005	BORDER_COLOR_B
$AF:0006	$AF:0006	BORDER_COLOR_G
$AF:0007	$AF:0007	BORDER_COLOR_R
$AF:0008	$AF:0008	BORDER_X_SIZE[5:0]
$AF:0009	$AF:0009	BORDER_Y_SIZE[5:0]
$AF:000A	$AF:000C	UNDEFINED - RESERVED
$AF:000D	$AF:000D	BACKGROUND_COLOR_B	Background Control Registers
$AF:000E	$AF:000E	BACKGROUND_COLOR_G
$AF:000F	$AF:000F	BACKGROUND_COLOR_R
$AF:0010	$AF:0010	VKY_TXT_CURSOR_CTRL_REG	Cursor Control Registers
$AF:0011	$AF:0011	VKY_TXT_START_ADD_PTR	This is an offset to change the Starting address of the Text Mode Buffer (in x)
$AF:0012	$AF:0012	VKY_TXT_CURSOR_CHAR_REG	Char used as the Cursor
$AF:0013	$AF:0013	VKY_TXT_CURSOR_COLR_REG	Color Choice for the Cursor
$AF:0014	$AF:0014	VKY_TXT_CURSOR_X_REG_L	Cursor Position X
$AF:0015	$AF:0015	VKY_TXT_CURSOR_X_REG_H
$AF:0016	$AF:0016	VKY_TXT_CURSOR_Y_REG_L	Cursor Position Y
$AF:0017	$AF:0017	VKY_TXT_CURSOR_Y_REG_H
$AF:0018	$AF:001B	VKY_LINE_IRQ_CTRL_REG	Line Interrupt Registers: [0] - Enable Line 0, [1] -Enable Line 1
$AF:001C	$AF:001C	VKY_INFO_CHIP_NUM_L	Read: Vicky Chip Part Number (L) - Write: LINE0_CMP_VALUE_LO
$AF:001D	$AF:001D	VKY_INFO_CHIP_NUM_H	Read: Vicky Chip Part Number (H) - Write: LINE0_CMP_VALUE_HI
$AF:001E	$AF:001E	VKY_INFO_CHIP_VER_L	Read: Vicky Chip Version (L) - Write: LINE1_CMP_VALUE_LO
$AF:001F	$AF:001F	VKY_INFO_CHIP_VER_H	Read: Vicky Chip Version (H) - Write: LINE1_CMP_VALUE_HI
$AF:0020	$AF:00FF	UNDEFINED - RESERVED
$AF:0100	$AF:0100	BM0_CONTROL_REG	First BitMap Plane
$AF:0101	$AF:0101	BM0_START_ADDY_L	Start Address Within the Video Memory (offset by $B0:0000)
$AF:0102	$AF:0102	BM0_START_ADDY_M
$AF:0103	$AF:0103	BM0_START_ADDY_H
$AF:0104	$AF:0104	BM0_X_OFFSET	Not implemented
$AF:0105	$AF:0105	BM0_Y_OFFSET	Not implemented
$AF:0106	$AF:0107	UNDEFINED - RESERVED
$AF:0108	$AF:0108	BM1_CONTROL_REG	Second BitMap Plane
$AF:0109	$AF:0109	BM1_START_ADDY_L	Start Address Within the Video Memory (offset by $B0:0000)
$AF:010A	$AF:010A	BM1_START_ADDY_M
$AF:010B	$AF:010B	BM1_START_ADDY_H
$AF:010C	$AF:010C	BM1_X_OFFSET	Not implemented
$AF:010D	$AF:010D	BM1_Y_OFFSET	Not implemented
$AF:010E	$AF:010F	UNDEFINED - RESERVED
$AF:0200	$AF:02FF	TILES Memory Map	Refer to Tiles
$AF:0300	$AF:03FF	Collision Detection Memory Map	Refer to Collision Detection
$AF:0400	$AF:04FF	VDMA_CONTROL_REG	Video DMA Block
$AF:0500	$AF:05FF	MOUSE_PTR_GRAPH0	16x16 Mem Block 0 for Mouse Pointer
$AF:0600	$AF:06FF	MOUSE_PTR_GRAPH1	16x16 Mem Block 1 for Mouse Pointer
$AF:0700	$AF:0700	MOUSE_PTR_CTRL_REG_L	Mouse Pointer Registers Block
$AF:0701	$AF:0701	MOUSE_PTR_CTRL_REG_H
$AF:0702	$AF:0702	MOUSE_PTR_X_POS_L	X Absolute Location of the Mouse
$AF:0703	$AF:0703	MOUSE_PTR_X_POS_H	Presently Read Only
$AF:0704	$AF:0704	MOUSE_PTR_Y_POS_L	Y Absolute Location of the Mouse
$AF:0705	$AF:0705	MOUSE_PTR_Y_POS_H	Presently Read Only
$AF:0706	$AF:0706	MOUSE_PTR_BYTE0	PS2 Mouse Packet Byte 0
$AF:0707	$AF:0707	MOUSE_PTR_BYTE1	PS2 Mouse Packet Byte 1
$AF:0708	$AF:0708	MOUSE_PTR_BYTE2	PS2 Mouse Packet Byte 2
$AF:0709	$AF:070A	UNDEFINED MOUSE
$AF:070B	$AF:070B	C256F_MODEL_MAJOR
$AF:070C	$AF:070C	C256F_MODEL_MINOR
$AF:070D	$AF:070D	FPGA_DOR (Day of Release)
$AF:070E	$AF:070E	FPGA_MOR (Month of Release)
$AF:070F	$AF:070F	FPGA_YOR (Year of Release)
$AF:0710	$AF:07FF	UNDEFINED - RESERVED	------------------------
$AF:0800	$AF:080F	RTC	See the RTC Section for more details
$AF:0810	$AF:0BFF	UNDEFINED - RESERVED	------------------------
$AF:0C00	$AF:0DFF	Sprites Memory Map	Refer to Sprites
$AF:0E00	$AF:0FFF	UNDEFINED - RESERVED	------------------------
$AF:1000	$AF:13FF	SUPERIO	See the Super IO Section for more details
$AF:1400	$AF:1F3F	UNDEFINED - RESERVED	------------------------
$AF:1F40	$AF:1F7F	FG_CHAR_LUT_PTR	Text Foreground Look-Up Table
$AF:1F80	$AF:1FFF	BG_CHAR_LUT_PTR	Text Background Look-Up Table
$AF:2000	$AF:23FF	GRPH_LUT0_PTR
$AF:2400	$AF:27FF	GRPH_LUT1_PTR
$AF:2800	$AF:2BFF	GRPH_LUT2_PTR
$AF:2C00	$AF:2FFF	GRPH_LUT3_PTR
$AF:3000	$AF:33FF	GRPH_LUT4_PTR	Not Implemented Yet
$AF:3400	$AF:37FF	GRPH_LUT5_PTR	Not Implemented Yet
$AF:3800	$AF:3BFF	GRPH_LUT6_PTR	Not Implemented Yet
$AF:3C00	$AF:3FFF	GRPH_LUT7_PTR	Not Implemented Yet
$AF:4000	$AF:40FF	GAMMA_B_LUT_PTR
$AF:4100	$AF:41FF	GAMMA_G_LUT_PTR
$AF:4200	$AF:42FF	GAMMA_R_LUT_PTR
$AF:4300	$AF:7FFF	UNDEFINED - RESERVED	------------------------
$AF:8000	$AF:87FF	FONT_MEMORY_BANK0	FONT Character Graphic Mem
$AF:8800	$AF:9FFF	UNDEFINED - RESERVED	------------------------
$AF:A000	$AF:BFFF	CS_TEXT_MEM_PTR	Text Memory Block
$AF:C000	$AF:DFFF	CS_COLOR_MEM_PTR	Color Text Memory Block

Modes

Modes are enabled and disabled via the Vicky Master Control Register at $AF0000 via the control bits:

Mstr_Ctrl_Text_Mode__Lo_En	= $01	Enable the Text Mode
Mstr_Ctrl_Text_Overlay	= $02	Enable the Overlay of the text mode on top of Graphic Mode (the Background Color is ignored)
Mstr_Ctrl_Graph_Mode_En	= $04	Enable the Graphic Mode
Mstr_Ctrl_Bitmap_En	= $08	Enable the Bitmap Module In Vicky
Mstr_Ctrl_TileMap_En	= $10	Enable the Tile Module in Vicky
Mstr_Ctrl_Sprite_En	= $20	Enable the Sprite Module in Vicky
Mstr_Ctrl_GAMMA_En	= $40	Enable the GAMMA correction - The Analog and DVI have different color values, the GAMMA is great to correct the difference
Mstr_Ctrl_Disable_Vid	= $80	This will disable the Scanning of the Video information in the 4Meg of VideoRAM hence giving 100% bandwidth to the CPU

The Video mode enables hi-resolution and pixel doubling which yields 4 resolutions: - 320 x 240 (pixel doubling, low res) - 400 x 300 (pixel doubling, hi res) - 640 x 480 (low res) - 800 x 600 (hi res)

Mstr_Ctrl_Video_Mode0	= $01	0 - 640x480 (Clock @ 25.175Mhz), 1 - 800x600 (Clock @ 40Mhz)
Mstr_Ctrl_Video_Mode1	= $02	0 - No Pixel Doubling, 1- Pixel Doubling (Reduce the Pixel Resolution by 2)

Bitmap Layer

The bitmaps are stored anywhere in video RAM, which starts at bank $B0. If the bitmap is starts at $B0:0000, the BM_START_ADDY has to be set to $00:0000. There are two bitmap planes.

• BM_CONTROL_REG = $AF:0100 and $AF:0108
  • Bit 0 = disable/enable
  • Bit 1-3 = Target LUT address located at AF:2000 and up.
  • Bit 6 = Bitmap Collision On
• BM_START_ADDY_L = $AF:0101 and $AF0109
• BM_START_ADDY_M = $AF:0102 and $AF:010A
• BM_START_ADDY_H = $AF:0103 and $AF:010B

Text Layer

This layer is enabled by setting the Vicky master control register at $AF0000 to have bit 1 enabled. To overlay text on a bitmap display set bit 2 enabled. This will ignore the background color so this bitmap image can show through.

The text layer text itself starts at address $AF:A000. At the moment this layer has 128 columns and 64 rows, of these 80 columns and 60 rows are visible on screen at any time. Do remember that Vicky is capable of displaying a border. Its up to the developer to account for the overlap of the border with the text screen and adjust the text position accordingly.

The fore and background color can be set by setting the corresponding bytes for each character starting at $AFC000. The upper 4 bits of every byte specify the foreground of the character and the lower 4 bytes specify the background color. This means that only 16 colors are available for the fore and background each. Both index into the text LUT for either fore or background color.

• Start of text screen = $AF:A000
• Start of color screen = $AF:C000
• Foreground LUT start = $AF:1F40 (4-bytes per entry)
• Background LUT start = $AF:1F80 (4-bytes per entry)

LUT

A LUT, namely a Look-Up-Table, stores a selection of colors. 256 colors are supported in the video composition for the bitmap layer. The text overlay LUT is limited to 16 colors for foreground and background colors each. All re selectable out of 16.777.216 colors in the 24 Bit RGB color scheme. The LUT also contains an 8 Bit alpha channel, though it isn't supported. In summary, the LUT has $400 (1024) bytes - and the order for composing it is B -> G -> R -> A.

As an example, if you would want to compose a LUT of 16 base colors, it would look like this:

Address	Hex Values (BGRA)	Decimal RGB Value
$AF:2000	-- Transparent --	-- Transparent --
$AF:2004	00 00 00 00	0, 0, 0
$AF:2008	FF FF FF 00	255, 255, 255
$AF:200C	00 00 88 00	0, 0, 136
$AF:2010	EE FF AA 00	238, 255, 170
$AF:2014	CC 44 CC 00	204, 68, 204
$AF:2018	55 CC 00 00	85, 204, 0
$AF:201C	AA 00 00 00	170, 0, 0
$AF:2020	77 EE EE 00	119, 238, 238
$AF:2024	55 88 DD 00	85, 136, 221
$AF:2028	00 44 66 00	0, 68, 102
$AF:202C	77 77 FF 00	119, 119, 255
$AF:2030	33 33 33 00	51, 51, 51
$AF:2034	77 77 77 00	119, 119, 119
$AF:2038	66 FF AA 00	102, 255, 170
$AF:203C	FF 88 00 00	255, 136, 0
$AF:2040	BB BB BB 00	187, 187, 187

Adressing anything in the LUT is achieved by simply dividing the lower 10 bits of target color address by 4.