System X and Coral66 This topic has 0 replies, 1 voice, and was last updated 8 years, 3 months ago by Wallis Dudhnath. Viewing 1 post (of 1 total) Author Posts 1st July 2015 at 15:47 #69788 Wallis DudhnathGuest Any questions or issues related to a System X Stored Program Control (SPC) switch. Vendor was GPT – GEC Plessey Telecoms. The programming language was based on (BT)Coral66. System X used a number of sub-systems: DSS, DSS, CAS, PUS (POPUS), etc.. Author Posts Viewing 1 post (of 1 total) The forum ‘Telecom Design’ is closed to new topics and replies.