There are a number of factors which limit the ease of transfer of mathematical software from one computer sytem to another. For FORTRAN implementations of mathematical and statistical algorithms, a primary portability problem is caused by necessary variation in machine dependent constants. The problem occurs for both decimal and machine-specific representations. Redish and Ward (1971) discuss the problem, and propose a solution. This note extends their ideas to additional constants and computer types.

Algorithm 179 (MDBETA) can be improved as shown.