KL10
From Computer History Wiki
The KL10 was the third generation of PDP-10 processors. It was built out of ECL, on hex cards. It was used in the DECsystem-10 models 1080 and 1090 systems (with an external memory bus, compatible with the earlier KA10 and KI10), and the DECSYSTEM-20 20xx systems (with an internal memory bus).