Routines
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29800: Print Character
Used by the routines at 24545, 29560, Score_1UP and PrintString.
Input
A ASCII value to print
HL Screen address
PrintScreen 29800 PUSH BC Stash BC, DE and HL on the stack.
29801 PUSH DE
29802 PUSH HL
29803 LD L,A Create an offset in HL.
29804 LD H,0
29806 ADD HL,HL HL=HL * 8.
29807 ADD HL,HL
29808 ADD HL,HL
29809 LD DE,(23606) DE=CHARS.
29813 ADD HL,DE DE=HL + 15360. For examples of usage;
Letter ASCII Value * 8 (offset) CHARS + offset
"U" 85 680 16040
"L" 76 608 15968
"T" 84 672 16032
"I" 73 584 15944
"M" 77 616 15976
"A" 65 520 15880
"T" 84 672 16032
"E" 69 552 15912
29814 EX DE,HL
Print the character to the screen.
29815 POP HL Restore HL, containing the screen buffer location, from the stack.
This entry point is used by the routine at 29560.
PrintScreen_0 29816 LD B,8 B=8 (8 rows of pixels).
PrintScreen_Loop 29818 LD A,(DE) Copy a byte from the font data to the screen buffer.
29819 LD (HL),A
29820 INC DE Increment the font data by one.
29821 INC H Move onto the next pixel line.
29822 DJNZ PrintScreen_Loop Decrease counter by one and loop back to PrintScreen_Loop until counter is zero.
29824 POP DE Restore DE and BC from the stack.
29825 POP BC
Reset HL and move to the next column, ready to print the next character.
29826 LD A,H H=H - 8 (reset the display line).
29827 SUB 8
29829 LD H,A
29830 INC L Increment screen column by one.
29831 RET Return.
View the equivalent code in;
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