Ubuntu Amstrad CPC emulators
Arnold
The original version (Arnold) hasn't been updated since 2004, but a newer one, Arnold-TNG, is also available. It is a fork of the old one, and supposedly works with PulseAudio.
Has a very basic UI for loading disk images, etc.
Download website: from BerliOS.
Compiling
Download and uncompress the source to a directory of your liking.
In a terminal, cd to the directory, then
cd src
./configure
If you get errors after running configure, that might be because you don't have the libraries and software required to build the emulator. Read readme.linux file in the emulator folder for more information, but you will need gcc, libsdl-dev, libgtk-dev or similar installed beforehand.
If no errors are printed, type:
make
Hopefully it will work! And it will have placed an 'arnold' executable file in the arnold directory.
You can simply cd to that directory and run the emulator:
./arnold
You'll get two windows, one with controls for 'inserting' disk images in the virtual drives, and another one containing the actual screen output of the emulated computer.
To load and run most games, type
RUN"
and press enter. It should work fine (assuming you've placed a game disk image on drive A).
Else you can type
cat
which is the 'old skool' style of ls. This will get you a list of files in the disk. Sometimes the way to run a game is to run a .BAS file. For example if you get this output:
Drive A: user 0
DATA.BIN 41K
PICTURE.BIN 17K
VIKINGS.BAS 1K
119k free
you have to type this to run the game:
run"vikings.bas
There's also a guide on the CPC wiki on how to run software on CPCs.
I've tested the emulator with my Logitech USB gamepad and it-just-works.
CPC4X
I haven't tested this one in a while, it might have stopped working since I used it last (around 2008 I think).
Roland (web based)
OK, this actually isn't an Ubuntu native emulator, but considering how far Javascript is going, it can be a real alternative for some people.
It's funny that its tagline is "Probably the worst Amstrad CPC emulator". It's also open source.