Logsim-8

LOGSIM-8 is an interactive digital logic simulator designed for the simulation of combinational and sequential logic circuits at the gate level. The program uses a simple simulation language consisting of logic statements (defining gates and functional elements like flip-flops) and control statements (for input, output, and cycle control). Variables are used to describe circuit connections and are initially undefined. LOGSIM-8 operates similarly to FOCAL, utilizing a command-mode interface where lines are stored in a buffer and executed in a non-ordered fashion based on the logic description rather than line numbers. The software supports standard logic gates such as NOT, OR, NOR, AND, NAND, and XOR, as well as several flip-flop functions. The documentation provides a detailed guide on the language syntax, error correction, operation modes, and includes several example implementations such as an ALU, a sequence recognizer, and a BCD counter.