Every computer has a graphics/video card; you can't render anything without one. If you mean a dedicated graphics card, as opposed to an integrated one that uses memory off the operating system, make sure your laptop is upgradeable in that department- they are often designed for only the RAM be upgradable. If you have a desktop, you should try to upgrade your RAM a bit, as any graphics card you would be recommended nowadays would, at the very least, turn your computer into an Xbox 360- stronger cards beating both HD consoles. Then you'll have no issues. Not that you couldn't look for weaker card.
If you have half a gig of memory, you should probably have at least 32 MB. 1 Ghz is the minimum benchmark for a lot of sixth generation console ports and graphically flexible PC games, such as Megaman X8 and Star Wars Battlefront, which is the highest caliber games you should really be attempting to run.
If you have an Intel integrated graphics chip, this should help:
You should be able to find some sort of graphical information in the Personalization section of the control panel regardless.
Also, I might be mistaken as to how demanding Minecraft is, I just know my integrated card rendered it too slowly for my taste.
The integrated graphics is 32-bit, if I' not mistaken... and this computer is a desktop, not a laptop