Werner Soekoe wrote: > I need to run a PIC16F84 on 4.194304 MHz .... would it hurt to run > a 4Mhz PIC at this speed, or should I rather opt for a 10Mhz PIC? Werner: All 16F84s are manufactured using the same die and the same process; the only thing that makes a -10 part different from a -4 part is that the -10 part has been TESTED (and passed) at 10 MHz. Microchip doesn't publicize any data on the number of chips that fail at 10 MHz but pass at 4, but the general feeling out here in the world is that the number must be very small. Many of us have played with PICs at high speeds; at room temperature, I got a PIC16C54-XT (the old name for the PIC16C54-04) to run at 45 MHz. It's EXTREMELY unlikely that a -4 part will fail at 4.194304 MHz; in fact, it's unlikely that it'll even exhibit ANY behavior outside of Microchip's published specs for the part. However... If you're going into large-scale production of your product, or if it's important that the PIC meet ALL of its published specs (current draw and temperature-range, particularly), then you should use a -10 part; if you use a -4, you won't have any recourse with Microchip should it fail. -Andy === Andrew Warren - fastfwd@ix.netcom.com === Fast Forward Engineering - San Diego, California === http://www.geocities.com/SiliconValley/2499