I don't want to be a "dork", but--
Actually ARM9 was not the chip from the N64, not sure where you got that from, but it was a MIPS, by NEC "VR4300"
ARM9 just recently came out.
Ofcoarse it doesn't really matter, but if you were for some reason getting ready to develop for NDS and was reading into N64 development, that would be a no-no.
also the ARM7 can control the touch screen but not the ARM9(the chip from the N64)
Actually ARM9 was not the chip from the N64, not sure where you got that from, but it was a MIPS, by NEC "VR4300"
ARM9 just recently came out.
Ofcoarse it doesn't really matter, but if you were for some reason getting ready to develop for NDS and was reading into N64 development, that would be a no-no.