CIDER integrates the DSIM simulator with Spice3. It provides accurate, one- and two-dimensional numerical device models based on the solution of Poisson's equation, and the electron and hole current-continuity equations. DSIM incorporates many of the same basic physical models found in the Stanford two-dimensional device simulator PISCES. Input to CIDER consists of a SPICE-like description of the circuit and its compact models, and PISCES-like descriptions of the structures of numerically modeled devices. As a result, CIDER should seem familiar to designers already accustomed to these two tools. The CIDER input format has great flexibility and allows access to physical model parameters. New physical models have been added to allow simulation of state-of-the-art devices. These include transverse field mobility degradation important in scaled-down MOSFETs and a polysilicon model for poly-emitter bipolar transistors. Temperature dependence has been included over the range from -50C to 150C. The numerical models can be used to simulate all the basic types of semiconductor devices: resistors, MOS capacitors, diodes, BJTs, JFETs and MOSFETs. BJTs and JFETs can be modeled with or without a substrate contact. Support has been added for the management of device internal states. Post-processing of device states can be performed using the ngnutmeg user interface.