diff --git a/os/README.md b/os/README.md
index 742b855..48b0aee 100644
--- a/os/README.md
+++ b/os/README.md
@@ -1,9 +1,10 @@
 ## Notes
 <!-- Table with .md and .pdf links -->
-| Name                   | .md                                     | .pdf                                     | Handwritten                                 | MCQs                                   | Worksheet | Worksheet with Answers |
-| ---------------------- | --------------------------------------- | ---------------------------------------- | ------------------------------------------- | -------------------------------------- | --------- | ---------------------- |
-| Thread Synchronisation | [1](notes/03-thread-synchronisation.md) | [2](notes/03-thread-synchronisation.pdf) | [3](notes/03-thread-synchronisation-hw.pdf) | [4](mcqs/03-thread-synchronisation.md) | _         | _                      |
-| Memory management     | [1](notes/04-memory-management.md)       | [2](notes/04-memory-management.pdf)       | [3](notes/04-memory-management-hw.pdf)       | [4](mcqs/04-memory-management.md)       | _         | _                      |
+| Name                       | .md                                     | .pdf                                     | Handwritten                                 | MCQs                                   | Worksheet | Worksheet with Answers |
+| -------------------------- | --------------------------------------- | ---------------------------------------- | ------------------------------------------- | -------------------------------------- | --------- | ---------------------- |
+| Operating Systems - Primer | [1](notes/01-os-primer.md)              | [2](notes/01-os-primer.pdf)              | [3](notes/01-os-primer-hw.pdf)              | [4](notes/01-os-primer-mcqs.pdf)       | -         | -                      |
+| Thread Synchronisation     | [1](notes/03-thread-synchronisation.md) | [2](notes/03-thread-synchronisation.pdf) | [3](notes/03-thread-synchronisation-hw.pdf) | [4](mcqs/03-thread-synchronisation.md) | _         | _                      |
+| Memory management          | [1](notes/04-memory-management.md)      | [2](notes/04-memory-management.pdf)      | [3](notes/04-memory-management-hw.pdf)      | [4](mcqs/04-memory-management.md)      | _         | _                      |
 
 ## Problem sets
 1. [**Print in order**](https://leetcode.com/problems/print-in-order/submissions/)