I believe that right now, yes, those are the only ones, but look for all new devices to have this feature, and even older ones may be retrofitted by Microchip in the future. As far as accuracy is concerned, the internal osc is an RC type, so don't expect incredible stability. This mode is definitely for non-time critical applications. The nominal 4MHz frequency is fairly good because Microchip added a "trimmer" register that adjusts the R component of the RC circuit (I assume) to correct an off frequency device. If you are using the UV erasable versions of these chips, make sure you read this value with your programmer _before_ you erase it, since the adjustment value erases too. There are ways to recalculate this value, but it's a lot easier if you just record it prior to erasing. CIAO - Martin. On Wed, 3 Dec 1997 09:41:52 -0600, "John A. Craft" wrote: >Are the 14000 and 12C50 the only PIC's that contain internal 4Mhz clocks? > >And how acurate are they? > >Thanks > >Jc. Martin R. Green elimar@NOSPAMbigfoot.com To reply, remove the NOSPAM from the return address. Stamp out SPAM everywhere!!!