This is the chip that we use as a controller on pretty much all of our boards. You can use the PIC16F648A instead; they are functionally identical, but your PIC programmer will need to be told which. The picture shows a PIC16F628; the PIC16F648 looks identical except the 2 is a 4... PIC16F648A has double EEPROM and flash memory compared with PIC16F628A.
From the Manufacturer:
This powerful (200 nanosecond instruction execution) yet easy-to-program (only 35 single word instructions) CMOS FLASH-based 8-bit microcontroller packs Microchip's powerful PIC architecture into an 18-pin package and is upwards compatible with the PIC16F628, PIC16C62XA, PIC16C5X and PIC12CXXX devices. The PIC16F628A features 4MHz internal oscillator, 128 bytes of EEPROM data memory, a capture/compare/PWM, a USART, 2 Comparators and a programmable voltage reference that make it ideal for analog/integrated level applications in automotive, industrial, appliances and consumer applications.
-- Main.AdrianBowyer - 06 Feb 2008