bit and timestamp

bit

Integer data type that can be 1 or 0. Integer values other than 0 or 1 are accepted, but are always interpreted as 1. Columns with a data type of bit cannot be NULL.

timestamp

Data type that is defined as varbinary(8). It requires 8 bytes of storage.

Sybase updates the timestamp column each time its row is modified. A table can have only one column of timestamp data type.