The single-scattering (or Born) approximation is the most fundamental assumption shared by all seismic imaging methods, and plays a crutial role in the non-linear waveform inversion, an iterative process of linearized inversions. The Born simulator (linearized forward map) shares a computational core with the corresponding simulator (forward map), which has been well implemented in the modeling package IWAVE. This report focuses on implementing the Born simulator based on IWAVE, and reviews the main adaptations we made in IWAVE to accommodate such an implementation in C++. Our goal is to construct a C++ wrapper of IWAVE, which fits into a general framework for inversion. This report is the first of several describing an implementation of such a wrapper.