$0900 to
$8000 when the game was loaded we have to apply an offset to find the appropriate spot in the raw disassmbly of
gridrunner.prg. This offset in the raw disassembly is
$1700:
$16FF: 20 18 18 JSR s1818
$1702: 18 CLC
$1703: 18 CLC
$1704: FF 18 18 .BYTE $FF,$18,$18 ;ISC s1818,X
$1707: 18 CLC
$1708: F0 20 BEQ b172A
$170A: 10 1F BPL b172B
$170C: 1F 10 20 .BYTE $1F,$10,$20 ;SLO $2010,X
$170F: F0 18 BEQ b1729
$1711: 18 CLC
$1712: 18 CLC
$1713: 18 CLC
$1714: BD C3 81 LDA f81C3,X