Routines
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C271: Scroll Screen Up
Used by the routine at PrintScreenCharacter.
Scrolls the screen up one character row.
ScrollScreenUp C271 PUSH HL Keep the caller's registers and point HL at the screen address 5080.
C272 PUSH DE
C273 PUSH BC
C274 LD HL,$5080
C277 LD DE,$5060 Take the screen.
C27A LD A,$08 Use 08.
ScrollScreenUp_Loop C27C PUSH HL Take a length of 80 entries.
C27D PUSH DE
C27E LD BC,$0080
C281 LDIR Scroll 80 bytes of this screen third down one character row.
C283 POP DE Jump back to ScrollScreenUp_Loop while the count is not finished.
C284 POP HL
C285 INC H
C286 INC D
C287 DEC A
C288 JR NZ,ScrollScreenUp_Loop
C28A LD HL,$50E0 Point HL at the screen address 50E0.
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