| Under Telephone History it says: > The current PABX-based system went live over the weekend of 27-29th July 1990 A PBX serving a whole country, even a small one, is wild. From what I could find [1] the system used was a UXD5 exchange [2] which is technically a PSTN exchange intended for rural areas and based off the Monarch 120 PBX [3]. The architecture of the UXD5 is common to a lot of telephone exchanges of the time (possibly modern ones as well?) with actor based message passing, actors running on different levels (more real time vs less real time) and a combination of assembly and a high level language (in this case, Coral [4]). Fascinating stuff. [1] https://techmonitor.ai/technology/cable_wireless_has_contrac... [2] https://sites.google.com/site/monarchcallconnectsystem/uxd5-... [3] https://sites.google.com/site/monarchcallconnectsystem/monar... [4] https://en.m.wikipedia.org/wiki/CORAL |