diff --git a/docs/images/operating-system-concepts-figure-1-19.png b/docs/images/operating-system-concepts-figure-1-19.png new file mode 100644 index 0000000..a827f3b Binary files /dev/null and b/docs/images/operating-system-concepts-figure-1-19.png differ diff --git a/docs/images/operating-system-concepts-figure-1-21.png b/docs/images/operating-system-concepts-figure-1-21.png new file mode 100644 index 0000000..4fa2628 Binary files /dev/null and b/docs/images/operating-system-concepts-figure-1-21.png differ diff --git a/docs/notes/operating-system-concepts.org.gpg b/docs/notes/operating-system-concepts.org.gpg index 3106a65..722dfc9 100644 Binary files a/docs/notes/operating-system-concepts.org.gpg and b/docs/notes/operating-system-concepts.org.gpg differ