Legacy test and measurement instruments face end-of-life problems, lack of replacement parts, and require ongoing maintenance and calibration. In most cases, said instruments reside in three-bay Automatic Test Equipment (ATE) that occupies significant floor space. Their dimensions and technical conditions require valuable storage space and cause countless project delays. The replacement of these instruments with PXI-based modules requires modifications and revalidation of old Test Programs Sets (TPS), which have been developed under old programming languages such as HP-Basic, Assembly, FORTRAN, and ATLAS. Changes to these software applications can be impractical due to the magnitude (budget and schedule) of such an effort. Until recently, said replacement was almost impossible from a technical aspect, due to the lack of modules with similar hardware capabilities, such as high-density switching or high-frequency RF modules. In this article, Ehud explains how with new PXI modules introduced to the market in growing numbers, the replacement of the legacy instruments is available without the modification of the legacy TPSs or their software drivers.