According to Wikipedia ( http://en.wikipedia.org/wiki/PowerBook_500_series#PCMCIA_.22card_cage.22 ) its 16bit word. But the last line of the "article" gets to me:
But as I see it on my PB190, 5300, and 1400, booting from the PCMCIA is twice as fast as booting from the IDE. The IDE I clocked at just over 15MB/sec and I believe is 8bit. These two reasons alone slows down a CF to boot from the IDE when compared to the PCMCIA.
With the other laptop as far as I know, the PCMCIA is straight to the main CPU. Using a second processor for signal processing only slows down the device as I see it.
But as I see it on my PB190, 5300, and 1400, booting from the PCMCIA is twice as fast as booting from the IDE. The IDE I clocked at just over 15MB/sec and I believe is 8bit. These two reasons alone slows down a CF to boot from the IDE when compared to the PCMCIA.