Routines
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27497: Print the score, lines total or hi-score (2)
Continues from the routine at 29613. Prepares the buffer at 58123 with the graphic data for the digits whose character codes are stored at 58112, then copies the graphic data to the screen at the location specified by DE.
Input
DE Display file address
27497 PUSH DE Save the display file address
27498 LD HL,58143 Clear the 21-byte buffer at 58123, which will hold the graphic data for the number to be printed (21 bytes = 7 pixel rows, 3 bytes per row)
27501 LD B,21
27503 LD (HL),0
27505 DEC L
27506 DJNZ 27503
27508 LD L,B HL=58112 (where the ASCII codes of the digits are stored)
27509 LD A,(HL) Pick up the ASCII code of the next digit
27510 AND A Have we done all the digits?
27511 JR Z,27552 Jump if so
27513 LD E,A E=ASCII code for the digit (48-57)
27514 LD D,215 Point DE at the appropriate entry in the table of font character bitmap widths at 55072
27516 INC HL Point HL at the next digit and save this address for later
27517 PUSH HL
27518 LD A,(DE) A=width of the font character bitmap (in pixels)
27519 LD C,A Copy this to C
27520 INC D Point DE at the next bitmap pixel column
27521 LD A,(DE) A=next pixel column of bitmap data for this digit
27522 LD L,31 Point HL at the last byte of the graphic data buffer
27524 LD B,7 There are 7 rows of pixels in the buffer
27526 RRCA Skip the bottom row of pixels in the bitmap data
27527 RRCA Roll a pixel column into the buffer
27528 RL (HL)
27530 DEC HL
27531 RL (HL)
27533 DEC HL
27534 RL (HL)
27536 DEC HL
27537 DJNZ 27527
27539 DEC C Next pixel column
27540 JP M,27548 Jump if we've done them all (plus a blank column)
27543 JR NZ,27520 Jump back until all the pixel columns of the bitmap for the digit have been done
27545 XOR A Then jump back to add a blank pixel column
27546 JR 27522
27548 POP HL HL=address of the next digit
27549 NOP
27550 JR 27509 Jump back to deal with this digit
The graphic data for the digits has been rolled into the buffer at 58123. Now we copy the buffer to the screen.
27552 LD L,11 HL=58123 (start address of the buffer)
27554 LD BC,2047 B=7 (number of pixel rows), C=255
27557 POP DE DE=appropriate display file address
27558 LD A,E
27559 LDI Copy three bytes (one pixel row) from the buffer to the screen
27561 LDI
27563 LDI
27565 LD E,A Point DE at the start of the next row down
27566 INC D
27567 DJNZ 27559 Jump back until all 7 pixel rows are done
27569 RET
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