Toshiba PORTEGE Z830 Satellite Z830 Maintenance Manual page 219

Tests and Diagnostics
C7h UltraDMA CRC error count Number of CRC errors occurred during
data transference in the UltraDMA mode
DFh Load/Unload retry count Number of reloads of more than a certain
amount of times
[CONFIDENTIAL] 3-115
PORTEGE Z830 Satellite Z830 Series Maintenance Manual (960-883)