a) Replace all LBFFF by 0BFFFh
b) Press <1>+<5>+<0> for unlimited fuel & credits :)))
c) see below

          call  L5F82
L4035:    call  L5F82
          call  L4780
***
          call  L5F82
L4035:    Halt
          call  L5F82
          call  L4780

          jmp   L6881
L4617:    xor   al, al
          call  L00D5
***
          jmp   L6881
L4617:    Halt
          xor   al, al
          call  L00D5

          ret
L4624:    mov   al, 003h
          call  L00D8
***
          ret
L4624:    Halt
          mov   al, 003h
          call  L00D8

          ret
L4633:    xor   al, al
          call  L00D8
***
          ret
L4633:    Halt
          xor   al, al
          call  L00D8

          ret
L4B00:    mov   bx, 00100h
L4B03:    dec_bx
          mov   al, bh
          or    al, bl
          jnz   L4B03
          ret
***
          ret
L4B00:    HaltEvery 4
          xor   bx,bx
          ret

          jmp   L0056
L69C5:    mov   al, 007h
          call  L0141
***
          jmp   L0056
L69C5:    Halt
          mov   al, 007h
          call  L0141

          call  L5C7E
L69E2:    mov   al, 005h
          call  L0141
***
          call  L5C7E
L69E2:    Halt
          mov   al, 005h
          call  L0141

          call  L5C7E
L6AB2:    mov   al, 007h
          call  L0141
***
          call  L5C7E
L6AB2:    Halt
          mov   al, 007h
          call  L0141

          mov   bx, 00800h
L7617:    mov   al, 00Ah
          mov   ds:[0E044h], al
***
          mov   bx, 00800h
L7617:    Halt
          mov   al, 00Ah
          mov   ds:[0E044h], al
