Fix Intel 4004 factual error

contents/embedded_sys/embedded_sys.qmd

@@ -55,7 +55,9 @@ Embedded systems are specialized forms of computing that do not resemble traditi
 
 ### Historical Background
 
-The lineage of embedded systems dates back to the 1960s, marked by the introduction of the first microprocessor, labeled as @fig-Intel4004. This groundbreaking development led to the creation of the inaugural embedded system used in the Apollo Guidance Computer, the primary navigational system for the Apollo spacecraft. Over subsequent years, the domain has expanded remarkably, finding utility in diverse sectors such as automotive electronics, consumer electronics, telecommunications, and healthcare.
+The lineage of embedded systems traces back to the 1960s, with the Apollo Guidance Computer (AGC) as a pioneering example. Developed for the Apollo spacecraft's navigational system, the AGC utilized integrated circuits, a significant advancement in electronics at the time. However, the introduction of the first commercially available microprocessor, the Intel 4004, in 1971 (@fig-Intel4004) marked a groundbreaking milestone for embedded systems. 
+
+While not directly related to the AGC's technology, the Intel 4004 paved the way for developing increasingly sophisticated and compact embedded systems. Over the subsequent years, microprocessor-based embedded systems have expanded remarkably, finding utility in diverse sectors such as automotive electronics, consumer devices, telecommunications, and healthcare. The advent of the microprocessor enabled embedded systems to become more powerful, flexible, and cost-effective, leading to their widespread adoption across industries.
 
 ![Intel 4004.](https://spectrum.ieee.org/media-library/photo-intel.jpg?id=25586036&width=500){#fig-Intel4004 width=70%}