(ecase sb!c:*backend-byte-order*
(:little-endian
(write-wordindexed address index low-bits)
- (write-wordindexed address index high-bits))
+ (write-wordindexed address (1+ index) high-bits))
(:big-endian
(write-wordindexed address index high-bits)
(write-wordindexed address (1+ index) low-bits)))))