i just bought a 1996 grand cherokee 4.0 with only 205,000kms and its refusing to start i bought a brand new battery and checked the alt its fine its all grounded fine but wont give enough battery to start please help just hoping its not the computer

Check your battery connections, they could be dirty or loose.

i seem to be computer 'tarded..

Does the starter spin the engine? A new battery should allow your starter to spin the engine nice and fast, with no slowing down or laboring. If it sounds like it's struggling to crank the engine, i'd replace the starter. Before you do that however, i'd remove the electrical connectors on the starter and clean them. If they're oily/dirty the starter may not be getting full voltage. Also, loosen the bolts that mount the starter to the block and spray some contact cleaner where the starter meets the block. The starter uses that as a ground. A dielectric grease on the contacts after cleaning will help too.
(be sure you disconnect the battery first if you try this)

Ahhhhh just hit with a hammer good as new

If you're leaning to the battery that you just put in new, try a jump and see if its starts. Many auto parts stores will test your starter for free. If its turning over sluggish, seems to me to be the starter or poor connection somewhere along the line. Maybe someone has messed with the distributor advance, that will make a motor seem to crank hard. jmho