They are very similar but you cannot upgrade it with a500 parts they are as compatable as a 1.3 a500 but because of the cdtv,s internal cd rom drive you lose a bit of the 1 meg of memory which might stop some programs from running.There is a slot in the front of the machine wich is under a cover wich can take a memory card or elbox have a 2 or 8 meg memory expansion . :-)
