| Routines

53B1: Clear the screen and request the input method (keyboard, joystick, Int2)

Used by the routine at 55A0.
53B1 | LD BC,$0280 | INK 0: PAPER 6 for the top 20 lines of screen
53B4 | LD DE,$5801
53B7 | LD HL,$5800
53BA | LD (HL),$30
53BC | LDIR
53BE | LD C,$80 | INK 6: PAPER 6 for the bottom 4 lines of screen
53C0 | LD (HL),$36
53C2 | LDIR
53C4 | CALL $53AB | Make a short beep
53C7 | LD H,$40 | Clear the top two-thirds of the display file
53C9 | LD D,H
53CA | LD (HL),L
53CB | LD B,$10
53CD | LDIR
53CF | LD B,$A0 | Clear the remainder of the screen, except the bottom 3 lines (which contain machine code)
53D1 | LD (HL),C
53D2 | INC L
53D3 | DJNZ $53D1
53D5 | LD L,B
53D6 | INC H
53D7 | BIT 3,H
53D9 | JR Z,$53CF
53DB | LD A,$80 | Set the column of the play area at the far left of the screen to 128
53DD | LD ($7FFF),A
53E0 | NOP |
53E1 | CALL $50A0 | Clear character buffer 0xD6 (for no good reason)
53E4 | LD A,$F6 | Message 0xF6: 'None/Cursor/Kempston/Int2? (N,C,K or I)'
53E6 | LD HL,$4040 | Print this message
53E9 | CALL $50BC
53EC | LD HL,$5C3B | Clear bit 5 at 5C3B, ready for future keypresses
53EF | RES 5,(HL)
53F1 | JP $54A0 |