Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: do you need to buy the chip to get the map or no
Document: I opted for free. However, I am tech savvy and still spent many, many hours of time getting my unit just right. For me these hours were partially fun and partially frustrating. Probably more of the latter. If you're not an engineer I would highly recommend paying extra for your Edge 800 with a bundled map. If you already have the unit and need a map, I highly recommend buying a MicroSD chip with the map pre-installed.
You're up and running. You can get this chip from ridewithgps dot com. One of the free options is openstreetmap dot org.The user interface is typical Garmin, bulky and not intuitive. You just have to spend some time playing with it. Note that although it is a touch screen, it's only just barely better than not having a touch screen. There's no "pinching" the screen to shrink or enlarge the map. There's no "swiping" the screen to move the map left or right.
The easiest, and most expensive, option is to simply buy your Edge 800 with a bundled map. Otherwise, it is a very steep learning curve for the first time user, especially if you're not super tech savvy.If you buy the unit with only the Base Map you will need to buy a map. It is available two ways: Free and not-free. As is normally the case with such things, free is not easy and not-free is easy.
But it is very fun to use. If you are considering cheaper models but are drooling over this one, then buy it. No, you do not need it. But you do not need to get up at 5:00 AM on a Sunday to go for a bike ride wearing Lycra tights either. You do it because it's fun. (Riding, not wearing tights.)
The data it records from workouts is pretty good (I have yet to get a heart monitor strap) but if you don't need the advanced features I'd just buy a simple cycle computer which can give you speed, time, distance, cadence and a host of other data for a fraction of the price. I use this:Sigma BC1609 Cycling Computer, Rear Wheel Sensor
That said, it's a very full-featured unit at a low price. I haven't felt the need to buy a SD card with additional mapping as I don't really use it for navigation and the default maps are good enough for my local area. The must-have accessory is probably a speed sensor. I live in an area with lots of trees and tall buildings and it can take a while to get a GPS fix - until then the unit isn't doing anything for you.
And whatever you do, if you're relying on Where To?, so that Garmin will give you the route, you need to use one of the two On Road alternatives, or else you'll get a straight line to your destination (and you also need Recalculate "on" or "prompted" for this purpose).Lock on Road appears not to affect Garmin's calculated route guidance, but simply the Unit's Map display.
I use the Edge without cadence and wheel sensors on the mountain bike and tandem (buy extra mounts or keep the Edge in you pocket).A couple of minor issues:  If I create a course on Garmin Connect and upload it to the Edge, it appears to defeat the turn by turn directions. In that case you have to check the map display to see how you are off course when you get the off course warning alarm. I already lost a cadence magnet off my frank arm.
That mean every day you need to remind the unit what your preferences are. For example, I did not want the "Recalculate Route" feature turned on which is the default setting. With this feature, if you make a wrong turn it will recalculate another route for you given the path that you are on. The unit should remember your preferences, not make you enter them over and over again.Would I buy the unit again? Absolutely.
I've been using this for about my 3rd week now. I have the worst sense of direction and need GPS as much as possible. More than that I am a fitness but in the extreme. I have 4 or 5 heart rate monitors. I buy them for everything. So when I got a nice new bike I of course had to add a computer to it. I got it with heart rate monitor and cadence sensors. My only complaint with this is setting up the cadence sensors.
Answer: You need to purchase a Micro SD card. An 8GB version is more then enough and costs $40 or so. I live in the US and Europe and have both maps loaded which is why I went with a larger card but I read that most folks can get away with a 3-4 Gb Micro SD card without running into storage issues. Most Garmins come with a base pre installed map (no route detail, like looking at a basic map) and also have the City Navigator bundled on a larger data card. In my case, I simply bought the micro sd card, put it into the Garmin, plug it into the computer, went to Garmins web site and downloaded the City Navigator Europe to my computer, then transferred that map onto my Garmins data card. When you plug in your Garmin with the data card already inserted you see two icons on your desktop. One is the Garmin device, the other is the micro sd card. Copy the maps to the SD card. Eject, done! If you want to swap between maps it's in your settings. Just select and go. I also recommend downloading the Garmin Updater app to keep your devices firmware and other features current.