nots

Author: brownsarahm

_toc.yml

@@ -37,6 +37,7 @@ parts:
       - file: notes/2023-04-06
       - file: notes/2023-04-11
       - file: notes/2023-04-13
+      - file: notes/2023-04-18
   - caption: Activities
     chapters:
     - file: activities/kwl

notes/2023-04-18.md

@@ -0,0 +1,235 @@
+---
+jupytext:
+  text_representation:
+    extension: .md
+    format_name: myst
+    format_version: 0.13
+    jupytext_version: 1.10.3
+kernelspec:
+  display_name: Python 3
+  language: python
+  name: python3
+---
+
+
+```{code-cell} ipython3
+:tags: ["remove-input"]
+
+from IPython.display import Markdown, display
+
+date = '2022-04-14'
+practice = '../_practice/' + date + '.md'
+prepare =  '../_prepare/' + date + '.md'
+```
+
+
+# What *is* a computer?
+
+
+- how, physically, do we get the components we have seen?
+- what other components do we need?
+- how are those implemented
+
+
+How have computers changed over time?
+
+- at the physical level
+- what was the context and motivation for these advances?
+- how does that context influence how we use computers today?
+- how does that influence computing as a discipline?
+
+
+## Let's start with a dictionary
+
+
+
+[we can start with a dictionary](https://www.oed.com/oed2/00045995)
+
+- note that this starts with reference to a person.
+
+
+
+### Computers as people
+
+ and this text this particular dictionary is useful because it also includes where does the term originated like where does in that particular usage start appearing and so these are these are pretty all right this is starting 1646 1707
+
+- Use of the word computer to refer to the person still common how recently  1950s
+- the movie [hidden figures](https://www.imdb.com/title/tt4846340/) is available on Disney+ with subscription or other streaming platforms for ~$4 streaming rental.
+- the book [hidden figures](https://uri-primo.hosted.exlibrisgroup.com/permalink/f/10nopmq/01URI_ALMA21128298920002396) is available at URI's library
+
+
+
+### Computers as Machines
+
+Computers as machines started later. We started with mechanical, analog and then moved to electronic and then digital. 
+
+### How much do we talk about computers?
+
+[how much do we talk about them changes over time ](https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&corpus=26&smoothing=7&case_insensitive=on&content=computer&direct_url=t4%3B%2Ccomputer%3B%2Cc0%3B%2Cs0%3B%3Bcomputer%3B%2Cc0%3B%3BComputer%3B%2Cc0%3B%3BCOMPUTER%3B%2Cc0#t4%3B%2Ccomputer%3B%2Cc0%3B%2Cs0%3B%3Bcomputer%3B%2Cc0%3B%3BComputer%3B%2Cc0%3B%3BCOMPUTER%3B%2Cc0)
+
+
+
+
+## Mechanical Calculators
+ how do we actually like physically make it be machine
+
+
+
+ well we've we've talked we handed out that like it's going to reduce down to or isn't my check and logical operations write those de back much further than
+
+
+ ![pascal](https://upload.wikimedia.org/wikipedia/commons/7/78/Pascaline-CnAM_823-1-IMG_1506-black.jpg)
+
+
+
+ what is the mechanical calculator it works by like incrementing it doesn't do the logic like they took not a binary representation it's not adding via input two numbers and then it goes forward its where's my income as you put in one number then you can add the next number and it kind of works the wheels have like the numbers on them and it uses like 9 supplement to carry over to the next bit so there's a gear that when it hits a certain point that turns the next year and then it goes for it any Castles in the Sky why the semi did
+
+
+**Why did he make this?**
+
+He was 18 and  his father was a tax commissioner in France and he wanted to like reduce his father's workload
+
+ so he invented this calulator machine and received roayl privilege from France in 1649 to be only person allowed to build a manufactured Computing a calculator is like mechanical calculators
+
+
+
+  ![pascal schematic](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Pascaline_-_top_view_and_mechanism.jpg/1920px-Pascaline_-_top_view_and_mechanism.jpg)
+
+
+
+```{note}
+Contrast this royal privelege with the 1970s where in resolving some other conflict, a court that declared the content of the computer that they cannot be found it at all and it's free for anyone to use the concept of a computer
+```
+
+
+##  How did this change over time?
+
+
+
+calculators that are still analog so they're still working with mechanical systems using Waze electricity becomes easier
+
+we can start doing like electrical signal processing so we can move analog signals and start doing our agents and calculations with those are not what was really used through for transmitting information like telegram telephone all of that is analog thing
+
+between Springs and dampers, the mechanical things are used to build these mechanical calculators and the electrical components so resistors transistors.
+
+
+
+[timeline of computing](https://www.computerhistory.org/timeline/computers/)
+
+
+
+### Model K Adder (1937)
+
+- George Stibitz took some pieces at home from work at Bell Laboratory and got it working on his kitchen table.
+- it can do four bit addition
+- uses a telephone relay switch or an electromechanical switch so they're using like a
+
+```{note}
+Relays are designed to repeat, or relay, a signal  to the next circuit to compelte long distance telegraphs and early telphone. As the signal transpits down the cable (one circuit) it gets weaker due to loss, so it has to be repeated at some point to amplify the magnitude of it for the next length of the journey.  
+```
+
+precursor to the complex number calculator
+ he demonstrated how this works in combination with Telegraph
+for the first remote access
+
+- complex number calulator was at Bell Labs in New York City at the time in 1940
+at a Confrence at Dartmouth in Hanover New Hampshire and he use a telegraph to do remote calculations on this calculator and bring them the numbers back
+
+### Intel 4004 (1971)
+
+- First commercially produced microprocessor
+- 2,250 transistors
+- Could perform up to 90,000 operations per second in four bit chunks
+- 740 kHz clock speed
+
+
+### So how do these thigns actually work
+
+- [We can build an adder mechanically with marbles and wood](https://www.youtube.com/watch?v=GcDshWmhF4A)
+
+As electricity became more available, they realized that in terms of mathematical operations, electrical components resemble springs and switches
+
+- first vaccuum tubes: or diodes
+- diodes prevent flow of electricity in one direction and allow in the other. they can be used to create circuits that behave like the logical operations, and create the gates.
+- diodes only are easy for `&` and `|` gates,
+- transistors can operate as a switch or amplifier and can also be used to build logic gates
+- they're faster, smaller, and better at more types of gates than diodes
+
+## Early Computers
+
+
+During this time small, lots of small computers were made, but each was made completely by its creators, there was no standards, per say.  
+
+These computers were also stored program computers. Meaning their operation at a program level was fixed by the circuitry.
+
+switch the circuit to do different things between the numbers so this would get us bitwise operations of an indoor and outdoor on our numbers
+
+
+
+
+## von Neumann Architecture
+
+
+
+![Von Neumann Architecturediagram ](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Von_Neumann_Architecture.svg/2560px-Von_Neumann_Architecture.svg.png)
+
+
+![a bit mroe detail](https://upload.wikimedia.org/wikipedia/commons/4/4e/Computer_Systems_-_Von_Neumann_Architecture_Large_poster_anchor_chart.svg)
+
+
+what else do we need besides ALU for to have like a whole computer
+
+we eventually need clocks to time things and synchronize things to like know when to clear and when to change so that you if you want to do multiple things in sequence you can do that what else you need or want to do multiple things in sequence but don't know what else we need a general now
+
+
+In 1945 we get a draft of a general template. This is basically what we use today.  
+
+
+
+
+## Storage
+
+
+- there are some thigns we have not yet seen in detail in that diagram
+- Ram Is Random Access we can access it whenever we want we can read and write to
+- ROM: is read only memory; the instructions are Permanently
+
+
+In the stored program computers, the programs were in ROM.
+
+The very earliest computers could not store any values without power.
+
+
+- Register: data currently processing
+- Memory: will be required for processing
+- Disk: long term storage
+
+
+
+## Questions After Class
+
+```{note}
+these are last semesters. i'm behind on the new ones
+```
+
+### What are the PC, MAR, MDR, etc. and what do they do
+
+They are various registers that each have a specific role.  Learning all of these these in more detail is a good Explore badge or a single one is in more practice.
+
+### how does a motherboard work with all of these
+
+A motherboard contains all most of those components.  This is also a good Deeper explroation.
+
+
+### When defining a computer, is it best to define the most current model of a computer? Or how everything functions bare bones?
+
+What definition dependsd on the context.  If you are talking to a child who is trying to learn basic typing they need to know different things than a teenager trying to choose what type of comptuer to bring to college, which is different than the model you need to keep in mind when you're working in a high level language, which is different than what you need when you are writing drivers.
+
+
+### How do Quantum computer logic gates differ from what we use now exactly
+
+Quantum computers operate on a fundamentally different object, instead of bits they have [qubits](https://quantum-computing.ibm.com/composer/docs/iqx/guide/the-qubit).  There represent, essetially some uncertainty, or randomness in the behavior, so then there are different operations needed.  
+
+URI has a [MS in Quantum Computing in the Physics Dept](https://web.uri.edu/physics/quantum/)
+
+