Update

history.md

@@ -58,6 +58,8 @@ Shortly after, on 29 October 1969, another historical event would happen that co
 
 1st January 1970 is nowadays set as the start of the **Unix epoch**. It is the date from which [Unix time](unix_time.md) is counted. During this time the **[Unix](unix.md) [operating system](os.md), one of the most influential operating systems** was being developed at [Bell Labs](bell_labs.md), mainly by [Ken Thompson](ken_thompson.md) and [Dennis Ritchie](dennis_ritchie.md). Along the way they developed the famous [Unix philosophy](unix_philosophy.md) and also the **[C programming language](c.md)**, perhaps the most influential programming language in history. Unix and C would shape the technology far into the future, a whole family of operating systems called Unix-like would be developed and regarded as the best operating systems thanks to their minimalist design.
 
+By 1977 ARPANET had about 60 nodes.
+
 In 1983 **[Richard Stallman](rms.md) announced his [GNU](gnu.md) project and invented [free (as in freedom) software](free_software.md)**, a kind of software that is freely shared and developed by the people so as to respect the users' freedom. This kind of ethical software stands opposed to the [proprietary](proprietary.md) corporate software, it would lead to creation of some of the most important software and to a whole revolution in software development and its licensing, it would spark the creation of other movements striving for keeping ethics in the information age.
 
 August 12 1981 would see the released of **[IBM PC](ibm_pc.md)**, a person computer based on open, modular architecture that would immediately be very successful and would become the [de-facto standard](de_facto_standard.md) of personal computers. IBM PC was the first of the kind of desktop computers we have today. It had 4.77 MHz [Intel 8088](intel.md) CPU, 16 kB of [RAM](ram.md) and used 5.25" [floppy disks](floppy.md).