DX200 telephone switching exchange was created around 1978 upon Intel's brand new 16-bit 8086 processor. The software architecture was based on easy implementation of specifications written in SDL and the implementation language was PLM. During 1980's the code generation was domewhat automatized with TNCODE macro processor. More detailed variant of SDL (SDL-88) was utilized in a new specification and implementation language TNSDL, which allowed more advanced programming and testing tools and fully automatized code generation.