Existing codes for solving ODE problems often do not completely satisfy the requirements of applications users. Users may desire detailed feedback or extensive controls over the progress of the solver towards a solution. Many contemporary codes are complex bodies of software built for fast and efficient execution. They are hard to modify or to enhance for such purposes as fine tuning or experimenting with new mathematical solution methods. A modular design for a general purpose ODE solver code which will overcome these difficulties has been proposed in overall terms . A detailed version of this design is discussed and a simple implementation based on the use of LMF methods is presented.