On 06/21/2016 09:24 AM, Paul Koning wrote: > I don't recognize "ILR". The control for central exchange (XJ > instruction) is is largely in the ECS coupler partly because some of > the exchange package state (RAX/FLX/MA) lives there, as does the > monitor mode flag. Also partly because XJ and RE/WE are 01 opcodes > that use the same address calculation. I think once you get past the > coupler into ECS itself and the ECS controller, there aren't any > execution-related bits. Not unless you count the Flag Register, > which is a set of mutexes operated on by ECS read/write operations.
ILR = "Interlock Register" It was mutex setup, but on a per-system, rather than as a global ECS thing like the flags register--and accessible only to PPs. Any word in it could be read by any PP. Either 64 or 128 bits located on PP channel 15 (octal). The only mention that I could find of it in the bitsavers collection was for the Cyber 74, but it was on lower Cybers as well. http://bitsavers.informatik.uni-stuttgart.de/pdf/cdc/cyber/cyber_70/60347400N_Cyber70_Model74_Comp_Sys_Vol1_Jun77.pdf PDF page 48. I don't know if it was a retrofit for older 6000 systems, but it would seem to make sense if it was. It simplified the RCH/DCH PP channel reservation calls enormously. --Chuck
