>Hi Viv
>
>>Hex adds nothing - it just a different way of writing/visualizing a number.
>
>Yes true for numeric fields. As per the VFP help, VarBinary can be used in BITTEST/SET() and VarBinary can be of 255 in length.
>
>Does this mean we have 255 options as we would have in a character field or so many bytes as compared to the double you suggested (double is 8 bytes with about 52 usable bits, this one can go upto 255 characters thus a proportionate no. of bits)?

No - Varbinary is just an array of bytes.

Worse yet. From BITTEST help: 'If the specified expression is not an integer, it is converted to an integer before performing the operation' so I was wrong about being able to use 52 bits, - looks like 31 is the limit. Could you divide the modules into logical groups of 31 or less and use a int for each group? Or maybe you'd be better served just using a lookup table?