forked from MirrorRepos/RomWBW
Wayne Warthen
1 year ago
25 changed files with 533 additions and 0 deletions
@ -0,0 +1,496 @@ |
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;====================================================================== |
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; VIDEO DRIVER FOR FPGA VGA |
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; http://s100computers.com/My%20System%20Pages/FPGA%20Z80%20SBC/FPGA%20Z80%20SBC.htm |
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; |
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; WRITTEN BY: WAYNE WARTHEN -- 9/2/2024 |
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;====================================================================== |
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; |
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; FPGA VGA EXPOSES A FRAME BUFFER STARTING AT $E000. |
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; PORT $08 CONTROLS ACCESS TO THE FRAME BUFFER. |
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; - WHEN $01, FRAME BUFFER APPEARS AT $E000 IN CPU ADDRESS SPACE |
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; - WHEN $00, FRAME BUFFER IS INACCESSIBLE BY CPU |
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; PORT $C0: SET/GET CURSOR COL |
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; PORT $C1: SET/GET CURSOR ROW |
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; PORT $C2: CONTROLS VGA OUTPUT |
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; BIT 0: BLUE |
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; BIT 1: GREEN |
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; BIT 2: RED |
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; BIT 3: UNUSED? |
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; BIT 4: CURSOR MODE |
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; BIT 5: CURSOR BLINK |
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; BIT 6: CURSOR ENABLE |
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; BIT 7: VGA SIGNAL OUTPUT ENABLE |
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; PORT $08: BUFFER SELECT, 1=SELECTED |
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; |
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; TODO: |
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; |
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;====================================================================== |
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; FPGA VGA DRIVER - CONSTANTS |
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;====================================================================== |
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; |
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FV_FBUF .EQU $E000 ; ADDRESS OF FRAME BUFFER |
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FV_BASE .EQU $C0 ; BASE I/O ADDRESS |
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FV_CCOL .EQU FV_BASE+0 ; CUR COL PORT |
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FV_CROW .EQU FV_BASE+1 ; CUR ROW PORT |
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FV_CTL .EQU FV_BASE+2 ; VGA CONTROL PORT |
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; |
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FV_BUFCTL .EQU $08 |
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; |
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FV_KBDDATA .EQU $03 |
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FV_KBDST .EQU $02 |
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; |
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FV_ROWS .EQU 40 |
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FV_COLS .EQU 80 |
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; |
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TERMENABLE .SET TRUE ; INCLUDE TERMINAL PSEUDODEVICE DRIVER |
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;;;KBDENABLE .SET TRUE ; INCLUDE KBD KEYBOARD SUPPORT |
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; |
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DEVECHO "FV: IO=" |
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DEVECHO FV_BASE |
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DEVECHO ", KBD MODE=FV" |
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DEVECHO ", KBD IO=" |
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DEVECHO FV_KBDDATA |
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DEVECHO "\n" |
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; |
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;====================================================================== |
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; FPGA VGA DRIVER - INITIALIZATION |
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;====================================================================== |
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; |
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FV_INIT: |
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LD IY,FV_IDAT ; POINTER TO INSTANCE DATA |
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; |
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CALL NEWLINE ; FORMATTING |
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PRTS("FV: IO=0x$") |
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LD A,FV_BASE |
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CALL PRTHEXBYTE |
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CALL FV_PROBE ; CHECK FOR HW PRESENCE |
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JR Z,FV_INIT1 ; CONTINUE IF HW PRESENT |
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; |
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; HARDWARE NOT PRESENT |
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PRTS(" NOT PRESENT$") |
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OR $FF ; SIGNAL FAILURE |
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RET |
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; |
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FV_INIT1: |
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; RECORD DRIVER ACTIVE |
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OR $FF |
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LD (FV_ACTIVE),A |
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; DISPLAY CONSOLE DIMENSIONS |
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LD A,FV_COLS |
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CALL PC_SPACE |
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CALL PRTDECB |
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LD A,'X' |
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CALL COUT |
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LD A,FV_ROWS |
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CALL PRTDECB |
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PRTS(" TEXT$") |
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|
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; HARDWARE INITIALIZATION |
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CALL FV_CRTINIT ; SETUP THE FPGA VGA CHIP REGISTERS |
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CALL FV_VDAINI ; INITIALIZE |
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;CALL KBD_INIT ; INITIALIZE KEYBOARD DRIVER |
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|
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; ADD OURSELVES TO VDA DISPATCH TABLE |
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LD BC,FV_FNTBL ; BC := FUNCTION TABLE ADDRESS |
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LD DE,FV_IDAT ; DE := FPGA VGA INSTANCE DATA PTR |
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CALL VDA_ADDENT ; ADD ENTRY, A := UNIT ASSIGNED |
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|
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; INITIALIZE EMULATION |
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LD C,A ; C := ASSIGNED VIDEO DEVICE NUM |
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LD DE,FV_FNTBL ; DE := FUNCTION TABLE ADDRESS |
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LD HL,FV_IDAT ; HL := FPGA VGA INSTANCE DATA PTR |
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CALL TERM_ATTACH ; DO IT |
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|
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XOR A ; SIGNAL SUCCESS |
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RET |
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; |
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;====================================================================== |
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; FPGA VGA DRIVER - VIDEO DISPLAY ADAPTER (VDA) FUNCTIONS |
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;====================================================================== |
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; |
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FV_FNTBL: |
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.DW FV_VDAINI |
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.DW FV_VDAQRY |
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.DW FV_VDARES |
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.DW FV_VDADEV |
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.DW FV_VDASCS |
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.DW FV_VDASCP |
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.DW FV_VDASAT |
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.DW FV_VDASCO |
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.DW FV_VDAWRC |
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.DW FV_VDAFIL |
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.DW FV_VDACPY |
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.DW FV_VDASCR |
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.DW FV_STAT |
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.DW FV_FLUSH |
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.DW FV_READ |
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.DW FV_VDARDC |
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#IF (($ - FV_FNTBL) != (VDA_FNCNT * 2)) |
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.ECHO "*** INVALID FV FUNCTION TABLE ***\n" |
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!!!!! |
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#ENDIF |
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|
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FV_VDAINI: |
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; RESET VDA |
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CALL FV_VDARES ; RESET VDA |
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LD HL,0 ; ZERO |
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LD (FV_POS),HL ; ... TO POSITION |
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LD A,' ' ; BLANK THE SCREEN |
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LD DE,FV_ROWS*FV_COLS ; FILL ENTIRE BUFFER |
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CALL FV_FILL ; DO IT |
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LD DE,0 ; ROW = 0, COL = 0 |
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CALL FV_XY ; SEND CURSOR TO TOP LEFT |
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CALL FV_SHOWCUR ; NOW SHOW THE CURSOR |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_VDAQRY: |
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LD C,$00 ; MODE ZERO IS ALL WE KNOW |
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LD D,FV_ROWS ; ROWS |
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LD E,FV_COLS ; COLS |
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LD HL,0 ; EXTRACTION OF CURRENT BITMAP DATA NOT SUPPORTED |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_VDARES: |
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CALL FV_CRTINIT |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_VDADEV: |
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LD D,VDADEV_FV ; D := DEVICE TYPE |
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LD E,0 ; E := PHYSICAL UNIT IS ALWAYS ZERO |
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LD H,0 ; H := 0, DRIVER HAS NO MODES |
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LD L,FV_BASE ; L := BASE I/O ADDRESS |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_VDASCS: |
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SYSCHKERR(ERR_NOTIMPL) ; NOT IMPLEMENTED (YET) |
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RET |
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|
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FV_VDASCP: |
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CALL FV_XY ; SET CURSOR POSITION |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_VDASAT: |
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; ATTRIBUTES NOT SUPPORTED BY HARDWARE |
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XOR A |
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RET |
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|
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FV_VDASCO: |
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; CHARACTER COLOR NOT SUPPORT BY HARDWARE |
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XOR A ; SIGNAL SUCCESS |
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RET ; DONE |
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|
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FV_VDAWRC: |
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LD A,E ; CHARACTER TO WRITE GOES IN A |
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CALL FV_PUTCHAR ; PUT IT ON THE SCREEN |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_VDAFIL: |
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LD A,E ; FILL CHARACTER GOES IN A |
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EX DE,HL ; FILL LENGTH GOES IN DE |
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CALL FV_FILL ; DO THE FILL |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_VDACPY: |
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; LENGTH IN HL, SOURCE ROW/COL IN DE, DEST IS FV_POS |
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; BLKCPY USES: HL=SOURCE, DE=DEST, BC=COUNT |
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PUSH HL ; SAVE LENGTH |
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CALL FV_XY2IDX ; ROW/COL IN DE -> SOURCE ADR IN HL |
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POP BC ; RECOVER LENGTH IN BC |
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LD DE,(FV_POS) ; PUT DEST IN DE |
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JP FV_BLKCPY ; DO A BLOCK COPY |
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|
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FV_VDASCR: |
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LD A,E ; LOAD E INTO A |
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OR A ; SET FLAGS |
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RET Z ; IF ZERO, WE ARE DONE |
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PUSH DE ; SAVE E |
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JP M,FV_VDASCR1 ; E IS NEGATIVE, REVERSE SCROLL |
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CALL FV_SCROLL ; SCROLL FORWARD ONE LINE |
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POP DE ; RECOVER E |
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DEC E ; DECREMENT IT |
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JR FV_VDASCR ; LOOP |
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FV_VDASCR1: |
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CALL FV_RSCROLL ; SCROLL REVERSE ONE LINE |
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POP DE ; RECOVER E |
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INC E ; INCREMENT IT |
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JR FV_VDASCR ; LOOP |
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|
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FV_STAT: |
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IN A,(FV_KBDST) ; GET STATUS |
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AND $01 ; ISOLATE DATA WAITING BIT |
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JP Z,CIO_IDLE ; NO DATA, EXIT VIA IDLE PROCESS |
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|
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FV_FLUSH: |
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XOR A ; SIGNAL SUCCESS |
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RET |
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|
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FV_READ: |
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CALL FV_STAT ; GET STATUS |
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JR Z,FV_READ ; LOOP TILL DATA READY |
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IN A,(FV_KBDDATA) ; GET BYTE |
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LD E,A ; PUT IN E FOR RETURN |
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XOR A ; SIGNAL SUCCESS |
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RET ; DONE |
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|
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;---------------------------------------------------------------------- |
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; READ VALUE AT CURRENT VDU BUFFER POSITION |
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; RETURN E = CHARACTER, B = COLOUR, C = ATTRIBUTES |
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;---------------------------------------------------------------------- |
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|
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FV_VDARDC: |
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CALL FV_GETCHAR ; GET THE CHARACTER AT CUR CUR POS |
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LD E,A ; PUT IN E |
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LD BC,0 ; COLOR AND ATTR NOT SUPPORTED |
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XOR A ; SIGNAL SUCCESS |
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RET |
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; |
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;====================================================================== |
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; FPGA VGA DRIVER - PRIVATE DRIVER FUNCTIONS |
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;====================================================================== |
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; |
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; |
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;---------------------------------------------------------------------- |
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; PROBE FOR FPGA VGA HARDWARE |
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;---------------------------------------------------------------------- |
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; |
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; ON RETURN, ZF SET INDICATES HARDWARE FOUND |
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; |
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FV_PROBE: |
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XOR A ; ASSUME H/W EXISTS |
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RET |
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; |
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;---------------------------------------------------------------------- |
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; CRTC DISPLAY CONTROLLER CHIP INITIALIZATION |
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;---------------------------------------------------------------------- |
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; |
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FV_CRTINIT: |
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LD A,%11001111 ; WHITE ON BLACK, CURSOR ON, ENABLE OUTPUT |
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OUT (FV_CTL),A ; WRITE TO CONTROL PORT |
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XOR A ; ZERO ACCUM |
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RET ; DONE |
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; |
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;---------------------------------------------------------------------- |
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; SET CURSOR POSITION TO ROW IN D AND COLUMN IN E |
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;---------------------------------------------------------------------- |
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; |
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FV_XY: |
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CALL FV_HIDECUR ; HIDE THE CURSOR |
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PUSH DE ; SAVE NEW POSITION FOR NOW |
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CALL FV_XY2IDX ; CONVERT ROW/COL TO BUF IDX |
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LD (FV_POS),HL ; SAVE THE RESULT (DISPLAY POSITION) |
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POP DE ; RECOVER INCOMING ROW/COL |
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LD A,D ; GET ROW |
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OUT (FV_CROW),A ; SET ROW REGISTER |
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LD A,E ; GET COL |
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INC A ; 1..79,0 (WHY???) |
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CP 80 ; COL 80? |
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JR NZ, FV_XY1 ; SKIP IF NOT |
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XOR A ; ELSE MAKE IT ZERO! |
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FV_XY1: |
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OUT (FV_CCOL),A ; SET COL REGISTER |
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JP FV_SHOWCUR ; SHOW THE CURSOR AND EXIT |
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; |
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;---------------------------------------------------------------------- |
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; CONVERT XY COORDINATES IN DE INTO LINEAR INDEX IN HL |
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; D=ROW, E=COL |
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;---------------------------------------------------------------------- |
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; |
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FV_XY2IDX: |
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LD A,E ; SAVE COLUMN NUMBER IN A |
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LD H,D ; SET H TO ROW NUMBER |
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LD E,FV_COLS ; SET E TO ROW LENGTH |
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CALL MULT8 ; MULTIPLY TO GET ROW OFFSET, H * E = HL, E=0, B=0 |
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LD E,A ; GET COLUMN BACK |
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ADD HL,DE ; ADD IT IN |
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RET ; RETURN |
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; |
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;---------------------------------------------------------------------- |
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; SHOW OR HIDE CURSOR |
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;---------------------------------------------------------------------- |
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; |
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FV_SHOWCUR: |
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LD A,%11001111 ; CONTROL PORT VALUE |
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;;;LD A,%11111111 ; CONTROL PORT VALUE |
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OUT (FV_CTL),A ; SET REGISTER |
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XOR A ; SIGNAL SUCCESS |
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RET ; DONE |
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; |
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FV_HIDECUR: |
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LD A,%11001111 ; CONTROL PORT VALUE |
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;;;LD A,%11111111 ; CONTROL PORT VALUE |
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OUT (FV_CTL),A ; SET REGISTER |
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XOR A ; SIGNAL SUCCESS |
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RET ; DONE |
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; |
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;---------------------------------------------------------------------- |
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; (DE)SELECT FRAME BUFFER |
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;---------------------------------------------------------------------- |
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; |
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FV_BUFSEL: |
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PUSH AF |
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LD A,$01 |
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OUT (FV_BUFCTL),A |
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POP AF |
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RET |
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; |
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FV_BUFDESEL: |
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PUSH AF |
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XOR A |
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OUT (FV_BUFCTL),A |
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POP AF |
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RET |
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; |
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;---------------------------------------------------------------------- |
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; WRITE VALUE IN A TO CURRENT VDU BUFFER POSITION, ADVANCE CURSOR |
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;---------------------------------------------------------------------- |
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; |
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FV_PUTCHAR: |
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; WRITE CHAR AT CURRENT CURSOR POSITION. |
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PUSH AF ; SAVE INCOMING CHAR |
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CALL FV_HIDECUR ; HIDE CURSOR |
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CALL FV_BUFSEL ; SELECT FRAME BUFFER |
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POP AF |
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LD HL,(FV_POS) ; GET CUR BUF POSITION |
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LD DE,FV_FBUF ; START OF FRAME BUF |
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ADD HL,DE ; ADD IT IN |
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LD (HL),A ; PUT THE CHAR |
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; |
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; SET NEW POSITION |
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LD HL,(FV_POS) ; GET POSITION |
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INC HL ; BUMP POSITION |
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LD (FV_POS),HL ; SAVE NEW POSITION |
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; |
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; PUT CUROR IN PLACE |
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LD DE,FV_COLS ; COLS PER LINE |
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CALL DIV16 ; BC=ROW, HL=COL |
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LD D,C |
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LD E,L |
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CALL FV_XY |
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CALL FV_BUFDESEL ; DESELECT FRAME BUFFER |
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JP FV_SHOWCUR ; SHOW IT AND RETURN |
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; |
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;---------------------------------------------------------------------- |
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; GET CHAR VALUE TO A FROM CURRENT VDU BUFFER POSITION |
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;---------------------------------------------------------------------- |
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; |
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FV_GETCHAR: |
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XOR A |
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RET |
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; |
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;---------------------------------------------------------------------- |
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; FILL AREA IN BUFFER WITH SPECIFIED CHARACTER AND CURRENT COLOR/ATTRIBUTE |
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; STARTING AT THE CURRENT FRAME BUFFER POSITION |
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; A: FILL CHARACTER |
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; DE: NUMBER OF CHARACTERS TO FILL |
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;---------------------------------------------------------------------- |
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; |
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FV_FILL: |
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PUSH AF ; SAVE INCOMING FILL CHAR |
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CALL FV_HIDECUR ; HIDE CURSOR |
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CALL FV_BUFSEL ; SELECT BUFFER |
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LD HL,(FV_POS) ; CUR POS TO HL |
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LD BC,FV_FBUF ; ADR OF FRAME |
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ADD HL,BC ; ADD IT IN |
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POP AF |
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LD C,A ; FILL CHAR TO C |
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FV_FILL1: |
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LD A,D ; CHECK FILL |
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OR E ; ... COUNTER |
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JR Z,FV_FILL2 ; DONE IF ZERO |
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LD (HL),C ; FILL ONE CHAR |
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INC HL ; BUMP BUF PTR |
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DEC DE ; DEC FILL COUNTER |
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JR FV_FILL1 ; LOOP |
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; |
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FV_FILL2: |
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CALL FV_BUFDESEL ; DESELECT BUFFER |
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JP FV_SHOWCUR ; EXIT VIA SHOW CURSOR |
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; |
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;---------------------------------------------------------------------- |
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; SCROLL ENTIRE SCREEN FORWARD BY ONE LINE (CURSOR POSITION UNCHANGED) |
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;---------------------------------------------------------------------- |
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; |
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FV_SCROLL: |
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CALL FV_BUFSEL ; SELECT FRAME BUFFER |
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; |
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; COPY "UP" ONE LINE |
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LD HL,FV_FBUF + FV_COLS ; FROM SECOND LINE |
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LD DE,FV_FBUF ; TO FIRST LINE |
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LD BC,+(FV_ROWS - 1) * FV_COLS ; ALL BUT ONE LINE |
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LDIR ; DO IT |
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; |
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; FILL LAST LINE OF SCREEN |
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LD HL,FV_FBUF + ((FV_ROWS - 1) * FV_COLS) ; LAST LINE |
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LD A,' ' ; FILL CHAR |
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LD (HL),A ; COPY 1 CHAR |
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LD DE,FV_FBUF + ((FV_ROWS - 1) * FV_COLS) + 1 ; SECOND POS IN LAST LINE |
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LD BC,FV_COLS - 1 ; COLS PER LINE - 1 |
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LDIR ; FILL IT |
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; |
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CALL FV_BUFDESEL ; DESELECT FRAME BUFFER |
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RET ; DONE |
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; |
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;---------------------------------------------------------------------- |
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; REVERSE SCROLL ENTIRE SCREEN BY ONE LINE (CURSOR POSITION UNCHANGED) |
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;---------------------------------------------------------------------- |
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; |
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FV_RSCROLL: |
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CALL FV_BUFSEL ; SELECT FRAME BUFFER |
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; |
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; COPY "DOWN" ONE LINE |
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LD HL,FV_FBUF + (FV_COLS * (FV_ROWS - 1)) - 1 ; FROM END OF SECOND TO LAST LINE |
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LD DE,FV_FBUF + (FV_COLS * FV_ROWS) - 1 ; TO END OF LAST LINE |
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LD BC,+(FV_ROWS - 1) * FV_COLS ; ALL BUT ONE LINE |
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LDDR ; DO IT IN REVERSE |
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; |
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; FILL FIRST LINE OF SCREEN |
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LD HL,FV_FBUF ; FIRST LINE |
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LD A,' ' ; FILL CHAR |
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LD (HL),A ; COPY 1 CHAR |
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LD DE,FV_FBUF + 1 ; SECOND POS IN FIRST LINE |
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LD BC,FV_COLS - 1 ; COLS PER LINE - 1 |
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LDIR ; FILL IT |
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; |
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CALL FV_BUFDESEL ; DESELECT FRAME BUFFER |
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RET ; DONE |
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; |
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;---------------------------------------------------------------------- |
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; BLOCK COPY BC BYTES FROM HL TO DE |
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;---------------------------------------------------------------------- |
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; |
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FV_BLKCPY: |
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|
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CALL FV_BUFSEL ; SELECT FRAME BUFFER |
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PUSH BC ; SAVE LENGTH |
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LD BC,FV_FBUF ; FRAME BUFFER ADR |
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ADD HL,BC ; ADD TO SOURCE |
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EX DE,HL ; EXCHANGE |
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ADD HL,BC ; ADD TO DEST |
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EX DE,HL ; EXCHANGE |
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POP BC ; RECOVER LENGTH |
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LDIR ; LDIR DOES THE COPY |
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CALL FV_BUFDESEL ; DESELECT FRAME BUFFER |
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RET ; DONE |
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; |
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;================================================================================================== |
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; FPGA VGA DRIVER - DATA |
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;================================================================================================== |
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; |
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FV_POS .DW 0 ; CURRENT DISPLAY POSITION |
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FV_ACTIVE .DB FALSE ; FLAG FOR DRIVER ACTIVE |
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; |
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;================================================================================================== |
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; VGA DRIVER - INSTANCE DATA |
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;================================================================================================== |
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; |
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FV_IDAT: |
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.DB KBDMODE_FV ; FPGA VGA KEYBOARD CONTROLLER |
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.DB FV_KBDST |
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.DB FV_KBDDATA |
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