How do I get my digital camera's memory pictures on my computer?

i have a pentax optio digital camera and when there is no memory card in it, it still takes pictures but saves it to the memory..i'm just wondering how to get the pictures off the camera memory and onto my computer?

Usually, there is a cable that connects the two units. Often it is a USB or mini-USB type.
Then there is a camera driver and or camera control program (Often comes on a CD) which runs on the computer with functions like download from camera & save pictures & print pictures etc.
The driver sometimes has to be installed separately before the other program will work.

You should have a USB cable that connects the camera to the computer. You connect it without the memory card in the camera. the computer will then be able to access the pics you have on their.
It might not come on as a camera icon. It may be seen as a user drive.

connect camera to computer with the usb cord
it is in the manual