PIC (Peripheral Interface Controller) is a microcontroller IC made by Microchip.
When power is applied to the chip, it starts executing a program stored in its memory. The program is created on a PC using free software from Microchip (MPLab) and the transferred to the chip with a programmer. You can buy one or quickly build your own programmer for the PIC.
Back in 1965, GI formed a Microelectronics Division, and indeed used this division to generate some of the earliest viable EPROM and EEPROM memory architectures. As you may be aware, the GI Microelectronucs Division were also responsible for a wide variety of digital and analog functions, in the AY3-xxxx and AY5-xxxx families.
GI also generated a 16 bit microprocessor, called the CP1600, in the early 70s. This was a reasonable microprocessor, but not particularly good at handling I/Os. For some very specific applications where good i/o handling was needed, GI designed a Peripheral Interface Controller (or PIC for short), in around 1975. It was designed to be very fast, since it was i/o handling for a 16 bit machine, but didn't need a huge amount of functionality, so its microcoded instruction set was small. Hopefully, you can see what's coming....yes, the architecture designed in '75 is substantially the PIC16C5x architecure today. Granted, the 1975 version was manufactured in NMOS, and was only available in masked ROM versions, but still a good little uC. The market, however, didn't particularly think so, and the PIC remained designed in at a handful of large customers only.
During the early 80s, GI took a long hard look at their business, and restructured, leaving them to concentrate on their core activities, which is essentially power semiconductors. Indeed they are still doing this very successfully now. GI Microelectronics Division became GI Microelectronics Inc (a wholly owned subsidiary), which in 85 was finally sold to venture capital investors, including the fab in Chandler, Arizona. The venture capital people took a long hard look at the products in the business, and got rid of most of it - all the AY3- and AY5- parts and a whole bunch of other stuff, leaving the core business of the PIC and the serial and parallel EEPROMs and the parallel EPROMs. A decision was taken to restart the new company, named Arizona Microchip Technology, with embedded control as its differentiator from the rest of the pack.
As part of this strategy, the PIC165x NMOS family was redesigned to use one of the other things that the fledgling company was good at, i.e. EPROM - the concept of the CMOS based, OTP and eraseable EPROM program memory PIC16C5x family was born.
Actually, the PIC architecture was first integrated by Signetics for a company in San Jose (Scientific Memory Systems) using Bipolar technology and dubbed the 8X300.
Prior to that, the architecture had been a scientific curiosity since its invention by Harvard University in a Defense Department funded competition that pitted Princeton against Harvard.
Princeton won the competition because the MTBF of the simpler single memory architecture was much better, albeit slower, than the Harvard submission. With the development of the transistor and IC's the Harvard Architecture is finally coming into its own.
Microchip has made a number of enhancements to the original architecture, and updated the functional blocks of the original design with modern advancements that are in concert with existing architectural processes and enabled by the low cost of semiconductors.