The Raspberry Pi 400 is billed as a complete desktop PC for under $100 ($99.99). Is this for real, considering the cheapest regular computers are around $300 (plus paying for Word and Excel)? Your intrepid correspondent here dives deep to bring you the truth.
The Raspberry Pi series of microcomputer have been around since 2011. A typical Raspberry Pi is a printed circuit board, about 3 inches by 5 inches, with a microprocessor chip, some RAM memory, and many input/output ports. These ports include four USB ports, two micro-HDMI monitor ports, an Ethernet LAN port, a 3.5 mm audio/visual jack, and special camera-related ports (which can also handle a touchscreen). Also, a port for a micro-SD memory card, which is where the operating system and apps and data reside. But wait, there’s more: in addition to Bluetooth and wi-fi capability, the Pi has a 40-pin port for input and output to interact with the physical world. All this for around $35! 
Developed by the British nonprofit Raspberry Pi Foundation as an affordable educational tool, millions of Raspberry Pi units have been purchased by students and techies to learn-as-you-play and to do some useful projects. I have been aware of these devices for years, but I have been put off by how many peripherals you have to add to get an actual working unit – you have to add a USB-C type power supply, a keyboard, a mouse, and a monitor or other display. And you have to make or buy a case to put the circuit board in. All of which seems like a sprawling mess of wires and stuff. Also, the Pi does not have the computing power and memory to graciously run Windows and Microsoft Office apps like Word. Instead, it uses a Linux operating system instead of Windows, and LibreOffice apps for word processing and spreadsheets. I have never used Linux; it sounded exotic, maybe with a steep learning curve.
However, the good folks at the Raspberry Pi Foundation have come out with a new package for the Pi. This is the Raspberry Pi 400. The computing guts are housed inside a keyboard, with all the ports in the back. Thus, they provide the case and a keyboard, all in one tidy package, for about $70. The 400 lacks a few of the input/output ports found on the regular Pi, namely the camera-related I/O and the 3.5 mm headphone/video jack, but retains the 40-pin I/O port. For $100 you can get the complete Raspberry Pi 400 Personal Computer kit which includes a power supply, a mouse, a micro-SD card with operating software, a cable for the monitor, and a thick manual. I finally succumbed and bought the complete kit.  (Tip: To get the $100 price, you may do better to find a physical store location like Micro Center, since sellers on Amazon mark it way up to around $160, or sometimes they substitute the bare keyboard for the full kit). You just need to supply a monitor or a TV that has an HDMI input. 
The User Experience
So, how good is the Raspberry Pi 400? I have been pleasantly surprised. First, there was almost no learning curve on using the operating system. The version of Linux that is on the microSD card and which gets booted into the working RAM has a very Windows-like visual interface. I did not have to type in any arcane commands. It was all obvious point and clicks to open apps and documents. It helps that this is a pretty simple system, so not a lot of choices to wade through.
I entered my LAN wi-fi password, and was immediately on the internet using the built-in generic Chrome (not Google Chrome) browser. With the recent, improved software on the Pi, it happily streamed YouTube videos, etc. The LibreOffice suite includes apps which have most of the capabilities of Microsoft Office Word, Excel, and PowerPoint. You can configure some settings in LibreOffice to get the appearances, menus, etc., to even more closely match the Office apps. LibreOffice can save and open files in standard Office formats ( .docx, .xlsx, etc.) so as to share files with the rest of the world. This is pretty good for free software.
I’d rate the keyboard experience as “OK”. The keys are full size, but the feel and the keyboard angle are enough different from my laptop that my typing was slow. Maybe that would improve with use. If I were going to do a lot of typing on this, I would prop it at a more horizontal angle and rest my wrists on a pad sitting in front of the keyboard, to replicate my hand position on my laptop.
I have not yet played around with the 40-pin I/O port on the Pi 400. That sets it apart from a regular PC, giving the user a means to read inputs from the physical world, analyze them, and output desired actions (e.g., operate the watering hoses in a greenhouse or garden, depending on temperature and dryness of the ground). There are zillions of plans available on line for projects controlled by Raspberry Pi’s. Some are practical, some involve robots, and some are just whimsical, like retro video games and like this sugar cube launcher, which measures the distance to a coffee cup and shoots a sugar cube through the air with a trajectory calculated to land it in the cup. And here are another 26 Awesome Uses for a Raspberry Pi , including stop-motion and time-lapse videos (may not work on Pi 400 because it lacks regular Raspberry camera interface) and turning your Raspberry into a Twitter bot or web server that can host your own blog site.
The Verdict: Is This a Real PC?
Would I recommend this as a primary computer? Well, maybe, for someone on an extreme budget or living in a low-income country, or for someone in a situation where their computer is liable to get lost or broken or stolen. After all, it can do practically anything that a regular PC can do (email, YouTube, word processing, etc.). One area it falls way short in is compute-intensive gaming, so it is not for you if you need realistic spatters on your screen for Call of Duty. Also, if you have to go out and buy a new $150 monitor to use it, the value proposition starts to fall apart, but usually you have an old monitor or TV around or can borrow one from someone.
The LibreOffice apps will do most of what Microsoft Office does. The Pi cannot download Office and run it offline. However, if you can’t live without the authentic Microsoft Word experience, you can use the Pi as a terminal to log into Microsoft 365 and pay for and run the Web version of Word, Excel, etc. Also, you can plug in a USB microphone and USB webcam and use the Pi with Zoom.
Here is a list of further recommended programs ( all open source, Linux compatible) to install on a Raspberry Pi. These include programs for photo editing, media streaming, gaming, and connecting to a VPN. Here are more tips on the Pi 400 for home office use, including printing and online collaboration tools.
So, yes, a Pi 400 can do most of what desktop PC does, all for $99.99 plus tax . Not to mention not paying an extra $150 or so for Microsoft Office. That said, most of us already have a portable laptop as our primary computer. We can carry it anywhere, and it has built-in display, camera, and speakers. And we have a large monitor on our desk for the desktop experience. For most of us, it is worth spending say $600 for our laptop-plus-monitor versus using an underpowered desktop PC tethered to a monitor and power cord.
So, realistically, most adults in the West would not probably choose the Pi 400 as their primary computer. However, it is a great little spare machine to have around for guests or for kids or for if something happens to your main PC. It can be a second PC on the corner of your desk to use while your main computer is tied up on a Zoom call. Multiple people (e.g. students in a classroom) can share a Pi, especially if each person has their own microSD card or USB to store their individual documents. You could use a Pi to stream music or video over some random speaker or monitor or TV or dedicate it to some similar specific purpose.
The software load includes Python, a popular programming language which may be worth learning. Also, the Linux operating system is very widespread in the computer world, powering most servers, so it can be useful to learn Linux as well. Although the newbie user will likely just use the Windows-like graphical user interface, the command line text Linux commands are available for use and practice on the Pi. The Pi 400 software also includes “Scratch”:
Scratch is an easy to use block-based visual programming software that can run on a Raspberry Pi. Using this tool, you will be able to create your very own animations, games, and more using a straightforward drag-and-drop interface. The Scratch software is a great way to get young people started with programming and develop a general interest in computing.
The Raspberry Pi is a powerful tool for interfacing with the physical world, in the “internet of things.” A tech-inclined person (including a high school student) can find or invent a variety of fun and useful projects which make use of the input/output capabilities of the Pi. Since the internet can be problematic for kids, these sorts of projects with the Pi can keep them busy and learning on a real computer without necessarily having routine internet access.
 I think one reason I got the Pi 400 was sheer nostalgia; my very first personal computer, purchased around 1985, was a Commodore 64. Like the Pi 400, the Commodore 64 was a low-cost keyboard with interface ports that you hooked up to a TV or monitor. I used the I/O port on the Commodore to control a Radio Shack robot arm, using relays on a printed circuit board that I etched myself. Good times.
 Normally, the sound output from the Pi 400 is transmitted to the monitor/TV along with the video in the HDMI. If you have some old monitor or TV that only has VGA video input, you can buy an adapter cable that converts HDMI to VGA (make sure you specify male/female correctly), but that only gets you the visual output. To hear the sound in this case, you’d have to either pair up an external Bluetooth speaker with the Bluetooth in the Pi, or plug in a USB speaker. (The other Raspberry Pi models, like the 4 B, include a 3.5 mm jack that sends both sound and video, so you could just plug in a headphone and skip the USB speaker).
A couple of random tips on the Pi 400 keyboard: The Raspberry key, near lower left, brings up the main menu. To get a clean shutdown, properly saving and closing documents and apps, use Fn F10. Another observation: You can run the Pi off a USB thumb drive instead of the micro-SD card, which can give faster performance and more storage.
 One learning I got from doing this review is that you could use your phone as a desktop PC: with an iPhone or iPad, for instance, you can drive an external monitor with a cable from the Lightning port, and use a Bluetooth keyboard/mouse for inputs. There are word processor and other apps that run on phones and tablets, including Microsoft Office. This should give a computing experience similar to that on a Raspberry Pi, although using iOS or Android-specific forms of the various apps.