diff --git a/project-3-sequential-logic/bit-register-hierarchy.md b/project-3-sequential-logic/bit-register-hierarchy.md
new file mode 100644
index 0000000..57b5f5d
--- /dev/null
+++ b/project-3-sequential-logic/bit-register-hierarchy.md
@@ -0,0 +1,5 @@
+000000 → register 0 in RAM8 #0
+000001 → register 1 in RAM8 #0
+000010 → register 2 in RAM8 #0
+...
+001000 → register 0 in RAM8 #1 (high bits changed)
diff --git a/project-3-sequential-logic/bit-reminder.md b/project-3-sequential-logic/bit-reminder.md
new file mode 100644
index 0000000..71c9fd8
--- /dev/null
+++ b/project-3-sequential-logic/bit-reminder.md
@@ -0,0 +1,4 @@
+Binary number: 1 0 1 1 0 1 0 1
+Bit indices: 7 6 5 4 3 2 1 0
+↑ ↑
+high/left low/right