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9.2.2.14 CRTC module

Version numbers: Major 1, Minor 1.

TypeNameDescription
Hardware options
WORDVADDR_MASKMask of the address bits valid when accessing the video memory
WORDVADDR_CHARSWITCHIf one bit in the video address is used to switch the character generator, it is masked here.
WORDVADDR_CHAROFFSETThe offset in characters in the character generator that CHARSWITCH switches.
WORDVADDR_REVSWITCHIf one bit in the video address inverts the screen, it is masked here.
WORDCHARGEN_MASKsize of character generator in byte - 1
WORDCHARGEN_OFFSEToffset given by external circuitry
BYTEHW_CURSORexternal hardware cursor circuitry enabled
BYTEHW_COLSnumber of displayed columns during one character clock cycle
BYTEHW_BLANKset if the hardware blank feature is available
CRTC register
20 BYTEREGISTERSregister DUMP of the CRTC registers 0-19.
CRTC internal registers
BYTEREGNOThe current index in the CRTC register file
BYTECHARThe current cycle within the current rasterline
BYTECHARLINEThe current character line
BYTEYCOUNTERThe current rasterline in the character
BYTECRSRCNTFramecounter for the blinking cursor
BYTECRSRSTATEif set the hardware cursor is visible
BYTECRSRLINESset if ycounter is within the active cursor rasterlines for a char
WORDCHARGEN_RELrelative base of currently used character generator in ROM (in byte)
WORDSCREEN_RELscreen address to load the counter at the beginning of the next rasterline
WORDVSYNCnumber of rasterlines left within vsync; 0 = not in vsync
BYTEVENABLEvertical enable flipflop; 1= display, 0= blank.
(VICE-dependent?) variables
WORDSCREEN_WIDTHwidth of the current display window
WORDSCREEN_HEIGHTheight of the current display window
WORDSCREEN_XOFFSETx position where the first character in a line starts in the window…
WORDHJITTER…but only after adding this jitter
WORDSCREEN_YOFFSETx position where the first character in a line starts in the window…
WORDFRAMELINESexpected number of rasterlines for the current frame
WORDCURRENT_LINEcurrent rasterline as seen from the CRTC
This value has been added in module version V1.1
BYTEFLAGBit 0: If 1 then bit in VADDR_REVSWITCH must be set for reverse; if 0 then bit must be cleared for reverse.

Here is the reference for the previous CRTC snapshot module. It is outdated and will not be read by this and later versions of VICE.

Version numbers: Major 0, Minor 0.

TypeNameDescription
BYTERASTERYThe number of clock cycles from rasterlines start
WORDRASTERLINEThe current rasterline
WORDADDRMASKThe address mask valid for the CRTC. All memory accesses are masked with this value
BYTEHWFLAGBit 0: 1= hardware cursor available. Bit 1: 1= number of columns is doubled by external hardware
20 BYTEREGISTERSregister DUMP of the CRTC registers 0-19.
BYTECRSRSTATEHardware cursor: Bits 0-3: frame counter till next crsr line toggle. Bit 7: 1= cursor line active

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