We explore the framework in the area of speculative design. We prototype a “DNA I/O” device to capture our vision of a future bio/digital system by exploring the question: “What if we can read/write human genetics information (DNA) in real time?” This speculation is based on the emerging technology in the areas of DNA sequencing chips, which allow for the full read of genomic DNA with ultra-high-speed on a small device; CRISPR-Cas9 for genome engineering inside the cell, Synthetic DNA, which is enabling the cycle of design, build, test, learn in synthetic biology by putting together oligonucleotides and their assembly into synthons, genes, circuits, and even entire genomes. By integrating these technologies into a device that allow for the reading/writing human DNA in real time, the user is becoming part of the bio/digital system using their body as the biological material. We imagine that a device will be able to store digital files inside human cells for real time. One gram of DNA stores 215 petabytes. Dynamically modifying human physicality through the modification of the genome could lead to the creation of a biological app store, a store for users to download biological program to run inside their body.