The design for a simple portable computer that only requires a pen and a piece of paper.
The computer consists of a sheet of paper that contains both the program as well as a number of data registers, that will be used to represent the contents of the registers.
To begin, the pen, representing the program counter, is positioned at the line 00 of a program. The instruction in that line is then processed by the user by either moving the pen(program counter), modifying the value of a data register or by checking if a data register has become “empty”(zeroed).