Chapter 1 What is a Raspberry Pi
So you got a Pi. What next?
So, what is this Raspberry pi, and the Linux it runs????
The Raspberry Pi started off with the model A as a project by some people in England to make a cheap simple computer for students to play with and learn programming. That was February 2012. Instead of a hard drive, the software is installed on a SD card, installed into a slot on the board. The monitor is an HDMI port, feeding a standard digital TV. A standard keyboard and mouse plug into one of the USB ports. The power supply is a cell phone charger. Plug a cat 5 cable into the jack, and you are up and running. They have maintained backward compatibility rather well, and all versions are roughly the size of a pack of cigarettes, and a price of $35. A later version is the model 3B+. It boasts a 4 core 1.4 Ghz processor with 1 GB ram, 4 USB ports, 1 GB wired internet connection with power over internet support, onboard Blue Tooth, Wifi b,g and n, and 5 Ghz, and a 40 pin header connection supporting a wide variety of digital I/O, and serial formats, and much more. Update: Now there is a Pi 4. It has a 64 bit quad core 1.5 GHz processor. 2, 4 or 8 Gb ram is available. Dual 4K monitor ports. 2.5 and 5 GHz wifi. Bluetooth 5.0. USB 2, and 3. And all the other standard features. Price starts at $35. They put a Pi 4 in a keyboard and call it a Pi 400. It sells for $70, or $100 for the kit including accessories.
They have started a second line, called the Pi Zero. It has a single core 1 Ghz processor, 512 Kb of ram, a micro USB port, mini HDMI port, and the same 40 pin header connection. It is a little bigger than a pack of gum, and prices at $5! They have a new model Pi Zero W, that includes on board Blue Tooth and Wifi b,g and n. This version is the same size and sells for $10.
They have now also introduced the Raspberry Pi Pico in January 2021 for $4.00. It has 264 Kb of ram, and 2 Mb of flash memory. It runs Micro Python, Circuit Python, C and Rust. It doesn't use a typical Keyboard and Monitor like all the other Pi's. You have an IDE (Integrated Development Environment) program you run on your computer to develop your programs and upload them to the Pico. The Pico is basically a controller, similar to an Arduino. Smaller than a stick of chewing gum... and for $4!!!
https://www.raspberrypi.org/products/ You can see the different models here, as well as investigate a wealth of info and software.
So, what about this thing called Linux??????
Initially, there was no version of Windows capable of operating on such a small performer with a strange processor. They have since come out with a Windows 10 meant for imbedded applications that is represented to work on the Pi. There are a dozen varieties of Linux now for the Pi as well. When you find a project that interests you, there is a 90 percent probability it will be based on Raspbian, now called the Raspberry Pi OS. The software comes in three versions. One is the full version with a desktop environment. The second is a Lite version. The third is a lighter desktop version. Everything is done by typing commands into a terminal. The first is more suitable to Newbies, the second more for Geeks. The third is for projects that don't need all the bells and whistles, but a desktop is handy. So, Linux was there, able to be scaled down to smaller systems, able to deal with different processors, and FREE!!!! Linux is distributed under GPL, General Public License. To greatly simplify it, you are free to use, modify and update / improve GPL software for free. You must provide your updates, whatever for free as well. You can charge for your labor to set up and maintain a system, but you can't charge for the software. There are thousands of programs that run on Linux, all for free.
Linux is a lot different than Windows. That will be covered further in WinVsLinux.txt
Jim Albrecht, K2BHM