Keyboard scanner 182 may be connected to keyboard 45 via a two-way hardware connection 184. Display periodic task 178 may be connected to a display memory 186 via a one-way data path towards display memory 186. The latter may be connected to liquid crystal display 38 via hardware connection...
I didn't know about the AlphaSmart's USB ports, but it's not enough. Imagine if you could plug a USB Hard Disk Drive, a printer, a scanner or a CD-Burner into those ports. It would certainly make the device more useful. Handspring Visor Neo --> Sony CLIE PEG-T665C --> palmOne...