In the warm glow of the MicroBasement, Jonathan A. Titus’s TRS-80 Interfacing Book 2 builds directly on the foundation laid in Book 1, taking TRS-80 owners into more advanced real-world hardware control and data acquisition. Published in 1980 by Howard W. Sams & Co. (ISBN 0-672-21739-2), this 256-page paperback expanded the interfacing toolkit with sophisticated projects involving analog signals, precise timing, serial communication, and multi-device systems. It showed hobbyists how to turn the TRS-80 into a powerful laboratory instrument, industrial controller, or data logger — all while keeping designs practical, low-cost, and buildable at home. In the MicroBasement collection, this sequel sits proudly beside Book 1, TRS-80 hardware, and Titus’s Mark-8 pages — proof that one good interfacing book deserves a worthy follow-up.
Jonathan A. Titus, the original Mark-8 designer and author of TRS-80 Interfacing Book 1, returned in 1980 with this advanced volume, again part of the Blacksburg Continuing Education Series from Howard W. Sams & Co. Drawing on feedback from readers who had mastered Book 1’s basics, Titus focused on more complex applications, deeper Z-80 programming, and integration with emerging peripherals. The book was aimed at TRS-80 Model I and Model III owners ready to move beyond simple I/O ports into serious experimentation and automation.
The book is structured for progressive building. It begins with a quick review of the TRS-80 expansion bus and Z-80 signals, then dives into advanced topics: analog-to-digital and digital-to-analog conversion (using chips like the ADC0808 and DAC0808), precise timing and event counting with counters and timers, serial RS-232 interfacing (with UARTs like the TR1602), interrupt-driven I/O for faster response, multi-channel data acquisition systems, stepper motor control with feedback, and opto-isolated interfaces for safety in real-world environments. Later chapters cover software techniques for polling vs. interrupt handling, data buffering, error checking, and complete project examples such as digital voltmeters, frequency counters, environmental monitors, and automated test equipment. Full schematics, timing diagrams, parts lists, Z-80 assembly code, and troubleshooting sections are included throughout.
Titus emphasized reliability and expandability: designs used common TTL and linear ICs, included power-supply isolation where needed, and provided code for both BASIC and assembly-language control. Projects were scalable — starting with simple add-ons like temperature sensors or relay drivers and building to full multi-channel systems. He addressed common pitfalls like bus noise, ground loops, and timing skew, making the book a trusted reference for anyone pushing the TRS-80 into laboratory, industrial, or educational applications. The total cost for most builds remained modest, often under $50–$100 in parts, keeping the barrier low for serious experimenters.
TRS-80 Interfacing Book 2 represents one of the critical turning points in the personal computing era. By extending Book 1’s foundation into analog interfacing, precise control, and data acquisition, Jonathan A. Titus transformed the TRS-80 from a home entertainment machine into a capable scientific and engineering tool. It inspired hobbyists, educators, and early entrepreneurs to build custom instruments and automation systems, helping bridge the gap between home computers and professional applications. Preserving and demonstrating this book is essential because it embodies the foundational efforts of engineers and authors who created the pathways for modern embedded systems, IoT, and sensor networks. In the MicroBasement, its pages rest beside Book 1, TRS-80 hardware, and Titus’s earlier Mark-8 work — a quiet reminder that with the right guide, an affordable computer could become the heart of real-world innovation and discovery.