I would appreciate some net-advice on how to drill a straight line of holes
at constant spacing and at a 45 degree angle to the surface of the wood.
Since I want to do this on the 2 inch surface of a 1x2x24, it is not
practical to drill perpendicular holes and them to slice the workpiece at 45
degrees.

The angle and the spacing must be held as constant as possible.

It is the same concept that is used in Cado modular furniture,

Let me try an ASCII drawing

__________________________________________________ __________________
\\ \\ \\ \\ \\ \\ \\
\\ \\ \\ \\ \\ \\ \\ 1"
__________________________________________________ __________________
24"

Any tips would be appreciated.

Larry