From acdb8a6286af132d6f79860b51749f69e744328c Mon Sep 17 00:00:00 2001
From: Anna <158518956+annaKann@users.noreply.github.com>
Date: Mon, 28 Apr 2025 14:57:40 -0400
Subject: [PATCH] Update 2025-04-17.md

practice-2025-04-17
---
 notes/2025-04-17.md | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/notes/2025-04-17.md b/notes/2025-04-17.md
index f063400..b6f6ee9 100644
--- a/notes/2025-04-17.md
+++ b/notes/2025-04-17.md
@@ -373,6 +373,21 @@ https://www.intel.com/content/www/us/en/history/museum-story-of-intel-4004.html#
 https://spectrum.ieee.org/chip-hall-of-fame-intel-4004-microprocessor
 
 ---
+# Explanation of the Control Unit (CU) - A part of the CPU
+## CU Description
+The control unit coordinates the activities of the CPU to ensure that all component parts collaborate to execute instructions properly and efficiently [1]. It does this by sending signals to other CPU components to tell each part what to do and when.
+
+## CU Build
+The CU is built using 2 main approaches: hardwared or microprogrammed.Both types manage execution by fetching instructions from memory, decoding them, and generating control signals to other CPU components. A hardwired CU uses fixed logic gates and circuits. Execution is faster with a hardwired CU, however, it is a fixed design.  A microprogrammed CU uses a mirocode, or set of microinstructions, stored in memory. Execution time is slower using a microprogrammed CU, but it is flexible, meaning it can be modified. [1]
+
+## CU Predecessors
+The engine control unit in the BMW Kommanogerat was the first automated device used to manage engine control functions. While not a part of a computer, this engine control unit has a similar concept to the CUs used today. [2] In later evolution, stored program designs, such as that found in the Harvard Mark 1 [3] used punched paper tape to sotre instructions, providing the first version of something that could fetch instructions in a computer. The sequence control unit would then execute one intruction at a time, similar to how a CU gets instructions and directs the execution of said instructions. 
+
+## Sources
+1. https://www.lenovo.com/gb/en/glossary/control-unit/#:~:text=The%20control%20unit%20is%20a,directing%20the%20execution%20of%20instructions.
+2. https://en.wikipedia.org/wiki/Engine_control_unit#:~:text=by%20how%20much.-,Early%20systems,cause%20surging%20and%20stalling%20problems.
+3. https://en.wikipedia.org/wiki/Central_processing_unit#:~:text=While%20von%20Neumann%20is%20most,tape%20rather%20than%20electronic%20memory.
+
 
 ## Scheduling Jobs
 Now that we're done with some history talk, let's go back to talking about connecting and working with remote servers.
@@ -414,4 +429,4 @@ Don't forget to logout of seawulf when done
 ```
 [ayman_sandouk@seawulf ~]$ logout
 Connection to seawulf.uri.edu closed.
-```
\ No newline at end of file
+```