SLDC51 - Version 4.1 Affordable, fast C Compiler for 8051 saves firmware development time SLDC51 (C compiler / debugger for 8051) from SPJ Systems generates fast, compact assembly code from the user's C program. It runs on DOS. It supports a subset of ANSI `C' with many 8051 specific extensions e.g. `bit' variables. The library includes a wide range of functions - string handling, conversions, I/O related and also math functions such as sin, cos etc. The SLD simulates the 8051 (and also commonly used peripherals such as LCD) on the PC. While single steping through your program, you can view / edit contents of Registers / Memory dump / SFRs / C variables or simulate input to peripherals.