Polish engineer Piotr Ostapowicz has created what may be the world's smallest 8-bit Atari computer recreation, the "Atarino". The entire system—processor, graphics chips, sound hardware, and memory controllers—fits on a module measuring just 2×1.5 centimeters (about 0.79×0.59 inches), roughly the size of a postage stamp:
An Advanced Cyber-Physical System Security Testbed for Substation Automation
Akila Herath, Chen-Ching Liu, Junho Hong, Mansi Girdhar
https://arxiv.org/abs/2505.24021