Manual for PIC Basic Pro, the PBP compiler that lets you write firmware for Microchip PIC microcontrollers in a BASIC dialect, filed as a 383 KB PDF.

Short 279 KB PDF datasheet for the Microchip PIC16C5xx family of baseline microcontrollers.

A general PIC reference document in PDF form, 869 KB in size. The name gives only a generic book title and no specific device, author or edition, so its exact contents…