| Routines

6FF4: Update the telephone icon

Used by the routine at 7425. The main entry point is used to make the telephone appear to vibrate as if ringing.
6FF4 | LD HL,$7032 | Point HL at the graphic data for the telephone when ringing (at 7032)
6FF7 | NOP |
6FF8 | JR $6FFD |
This entry point is also used by the routine at 7425 to make the telephone appear still (as between rings, or when not ringing).
6FFA | LD HL,$7045 | Point HL at the graphic data for the telephone when not ringing (at 7045)
6FFD | LD DE,$50AE | Point DE at the display file address of the top pixel row of the top-left tile of the telephone icon
7000 | LD A,$06 | Update the top six pixel rows of the top two tiles of the telephone icon
7002 | LDI
7004 | LDI
7006 | DEC E
7007 | DEC E
7008 | INC D
7009 | DEC A
700A | JR NZ,$7002
700C | LD A,(HL) | Update the bottom two pixel rows of the top-left tile of the telephone icon
700D | LD (DE),A
700E | INC L
700F | INC D
7010 | LD A,(HL)
7011 | LD (DE),A
7012 | LD B,$03 | There are three more pixel rows to update
7014 | LD DE,$50CE | Point DE at the display file address of the top pixel row of the bottom-left tile of the telephone icon
7017 | INC L | Update the top three pixel rows of the bottom-left tile of the telephone icon
7018 | LD A,(HL)
7019 | LD (DE),A
701A | INC D
701B | DJNZ $7017
701D | RET |