The Tandy Pocket Computers, sold by Radio Shack, were in a unique position as they fell between calculators and full-blown computers. To do anything interesting on these devices, users needed to turn to assembly language. However, as Old Vintage Computing Research discovered, the assembly for these pocket computers was particularly strange, even for an assembly language. There is a reason behind this peculiarity, and it has been explored in a detailed dive into the machine code history of the device.
The story begins with the Japanese government’s decision in 1969 to create a fictitious instruction set and architecture for the Information Technology Engineer exam. This was done to ensure that individuals who knew a specific computer would not have an unfair advantage in the exam. However, Japanese manufacturers later started producing computers that utilized this architecture, known as COMP-X, with the accompanying assembler named CAP-X. The blog post covers the extensive history of machines that either used the architecture or emulated it, dating back to the 1970s, and eventually, this unique architecture ended up in the Sharp and Casio pocket computers that were branded and sold by Radio Shack.
The Japanese origin of the architecture sheds light on why the assembly language for the Tandy Pocket Computers is so unusual. The influence of a fictitious architecture created for the purpose of a standardized exam permeated the design and functionality of these pocket computers. This revelation provides a fascinating insight into the unique history and development of these devices, further deepening the understanding of their inner workings and the cultural context in which they were conceived.
In summary, the Tandy Pocket Computer Assembly’s peculiarity has been attributed to its utilization of the COMP-X architecture, which originated as a simulated platform for a standardized exam in Japan. The unexpected influence of this fictitious architecture on real-world computing devices, and subsequently on the Tandy Pocket Computers, adds an intriguing layer to the history and functionality of these pocket devices. As enthusiasts and researchers continue to delve into the machine code history of vintage computing devices, uncovering such hidden and unexpected connections provides valuable insights into the evolution of technology and its intersection with broader societal and cultural influences.