The z-transform, the inverse z-transform, the relation between z and stransforms, mapping the s-plane into the z-plane, bilinear transformations, discretecontrol system, data hold element. Sampled data control systems, Stability of digitalsystems, optimal discrete control use of digital computers in AFCSS, digital-to-analogconversion, analog-to-digital conversion, discrete state equations, A Lyapunov scheme,parameter adaptation scheme, digital controller design, Aircraft landing system andservomotor system.