Just an add on to this thread.
I remember working with a lot of Resource Management documentation that helped with MML – Man Machine Language – commands.
I remember working with the following systems (and subsystems):
PUS – Processor
DSS – Switch
DSSS – Concentrator
SIS – Signalling Interworking
MCS – Maintenance Control system
CPS – Call processing subsystem
CAS – Call Accounting
NSS – Network Synch.
Code used was (BT)Coral66. DCD was used with the data. Numerous BA / BB / etc.. “cards” were used with the DCD.
VBR/ Wallis Dudhnath