Yes. OS/5 devices use memory mapping, and Sony devices run applications in user mode. While memory mapping could be used to prevent coprocessor register access, it is not. PNOlets can access system registers, even on the user mode devices. The game is that many of the devices remap the registers to different addresses than the chip manufacturer specifies. There are a number of queries in the archives about "where are the system registers on device x".
Several mappings that I know of are that the Tungsten/T uses identity mapping (registers are exactly where TI says they are), and the Tungsten/T3 moves registers at 4xxxxxxx to 9xxxxxxx. The TI watchdog timer on the Zire 71 is at FFFEC800. -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
