| Startup routine

81B4: Start

We jump here from the load routine at 802F.
81B4 | LD SP,$5CFE | Put the stack somewhere safe
81B7 | EI | Enable interrupts
81B8 | LD HL,$4000 | Copy the top character line of the display file (8x32 bytes) to the third character line from the bottom
81BB | LD DE,$50A0
81BE | CALL $50E5
81C1 | LD H,$B7 | Fill in the second character line from the bottom with the necessary code
81C3 | LD DE,$50C0
81C6 | CALL $50E5
81C9 | LD DE,$5D00 |
81CC | CALL $54F2 | Prepare 5D00 to 5DFF
81CF | CALL $54F2 | Prepare 5E00 to 5EFF
81D2 | CALL $54F2 | Prepare 5F00 to 5FFF
81D5 | LD DE,$8000 | Copy 256 bytes from E300 to 8000
81D8 | LD BC,$0100
81DB | LD HL,$E300
81DE | LDIR
81E0 | LD H,$61 | Move 7936 bytes from 6100 down to 6000
81E2 | LD D,$60
81E4 | LD B,$1F
81E6 | LDIR
81E8 | LD B,$FC |
81EA | LD (DE),A | Zero out addresses 7F00 to 7FFB (the game status buffer)
81EB | INC E
81EC | DJNZ $81EA
81EE | LD DE,$8100 | Prepare to copy 256 bytes from 5B00 to 8100 (thus overwriting this routine)
81F1 | LD HL,$5B00
81F4 | INC B
81F5 | JP $55A0 |