If you want to check the behaviour of an electronic circuit at low voltages, an adjustable power supply as shown here may be helpful. Powered from a 3 to 16 volts source (DC for sure), it will provide a stable output voltage in the 0 to 1.5 V range.
Click below to download a PDF copy of this article from Elektor magazine.
This book is a practical guide to processor design in the real world. It presents the Verilog HDL in an easily digestible fashion and serves as a thorough introduction about reducing a computer architecture and instruction set to practice.