Many of the architectural features described here evolved further before Keykos was implemented. Some involved moving kernel function to domain code; some features were simplified. The eventual design was much improved, I think.

There was also a significant change in the style of description. Jordan’s paper speaks of a variety of calls on the kernel, some passing keys. The new conception is to describe certain objects as implemented in the kernel, accessed by keys, with the notion of ‘system call’ replaced by invoking one of these keys.

Here are other terminology shifts that might ease reading the paper:

• “System Monitor” meant what “Kernel” now means.
• “RAD” referred to a magnetic drum that was rather faster than disks. The 940 swapped on a RAD.
• “core” has been replaced by RAM.
• The 940 “executive” is much like today’s shell.
• “Key” was short for capability.
• “Process” meant nearly what the Keykos “domain” means.
• The “Account” mechanism was simplified to form the Keykos meters.
• Keykos has no primitive “events” but does have ‘wait keys’.
• The described ‘key pages’ are approximately Keykos nodes.