That’s the reason for the vast versions of SPICE available now decades after the original was released, not all of which are as open or free as we might like. Qucs is a GPL circuit simulator.

is a free cross-platform software that works on Windows, macOS, and Linux. KiCAD combines three things, a Schematic editor, PCB editor, and 3-D viewer to create schematics, design PCB circuits ...

Design of CMOS digital integrated circuits, concentrating on device, circuit, and architectural issues. Analysis and design techniques in custom integrated circuit design, standard cells, memory. Use ...

but they do affect the overall design. The first is the Vbe drop. For a normal silicon transistor, this should be about 0.6 or 0.7 volts, dependant on temperature. If the real circuit or an ...