Routines
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73CD: Print Character
Used by the routines at DisplayPlayerLives, Score_1UP and PrintString.
Input
A ASCII value to print
HL Screen address
PrintScreen 73CD PUSH BC Stash BC, DE and HL on the stack.
73CE PUSH DE
73CF PUSH HL
73D0 LD L,A Create an offset in HL.
73D1 LD H,$00
73D3 ADD HL,HL HL=HL * 8.
73D4 ADD HL,HL
73D5 ADD HL,HL
73D6 LD DE,($5C36) DE=CHARS.
73DA ADD HL,DE DE=HL + 3C00. For examples of usage;
Letter ASCII Value * 8 (offset) CHARS + offset
"U" 55 02A8 3EA8
"L" 4C 0260 3E60
"T" 54 02A0 3EA0
"I" 49 0248 3E48
"M" 4D 0268 3E68
"A" 41 0208 3E08
"T" 54 02A0 3EA0
"E" 45 0228 3E28
73DB EX DE,HL
Print the character to the screen.
73DC POP HL Restore HL, containing the screen buffer location, from the stack.
This entry point is used by the routine at DisplayPlayerLives.
PrintScreen_0 73DD LD B,$08 B=08 (08 rows of pixels).
PrintScreen_Loop 73DF LD A,(DE) Copy a byte from the font data to the screen buffer.
73E0 LD (HL),A
73E1 INC DE Increment the font data by one.
73E2 INC H Move onto the next pixel line.
73E3 DJNZ PrintScreen_Loop Decrease counter by one and loop back to PrintScreen_Loop until counter is zero.
73E5 POP DE Restore DE and BC from the stack.
73E6 POP BC
Reset HL and move to the next column, ready to print the next character.
73E7 LD A,H H=H - 08 (reset the display line).
73E8 SUB $08
73EA LD H,A
73EB INC L Increment screen column by one.
73EC RET Return.
View the equivalent code in;
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