Apple PC, though not called PC sometimes, used DVD recorders (for computers) and those accounted for quite a large percentage of total DVD recorders shipped. But soon Philips and Ricoh made 1st and 2nd generation DVD+RW drives and Dell and HP became the largest PC vendors of DVD recorders. Later, NEC and Pioneer. Now, LG (HLDS) is the largest.
Yes, Apple tried to bite too many at once. Hmm... Newton as well. Now, HP, Sony, LG, BenQ... these are the biggest leaders in PDA and most of the portable computing markets are owned by Chinese-Taiwanese companies. Once Apple also had bigger profits and revenues than Microsoft and Intel. Now Apple seems to concentrate on iPod. Before Apple, the portable audio player market was lead by iRiver, a tiny company made up of primarily engineers. Instead of replacing Intel, Microsoft, and HP, Apple replaced that tiny company in still another market.
BTW, most audio players based only on memory chips are as small as that. Even my MP3 phones are not that big.