October 1-3, 2021

Springfield, OH

Tandy Tech Track

Tandy Tech Track is our special Friday event which consists of a set of highly-technical and informative classes taught by some of the leading figures in the vintage Tandy Radio Shack TRS-80 community. The Tech Track classes will be held in the speakers room. There is an additional cost to attend Tandy Tech Track on Friday.


  • Tandy Tech Track Attendee: $30 includes one entry fee for all 3 days
  • Tandy Tech Track Exhibitor: $50 includes one exhibitor table and one entry fee for all 3 days
  • All proceeds pay for the costs of running the event.

The Classes


Title: Getting Started: Practical TRS-80 Z80 Assembly Language Programming in the Modern Era

Instructor: Tim Halloran

Abstract: This talk presents practical techniques to help get you started in assembly programming for a Z80-based TRS-80 in 2021, regardless if you have a real machine or use emulators. You'll learn how to take advantage of your Windows, Mac, or Linux machine to author code for your TRS-80 Model 1, 3, or 4 (or emulator) with an ease that would pleasantly surprise assembly programmers from the late 70s (who dealt with a tremendous amount of accidental complexity). This talk will start with the basics and assume no prior assembly language experience. We'll focus on taking simple assembly programs from coding, to running on an emulator, and then to a real TRS-80. The goal of this talk is get you started down the road toward creating the next great TRS-80 text adventure or "Big 5"-style arcade game.

Bio: Tim Halloran has a Ph.D. in Software Engineering from Carnegie Mellon University, a M.S. in Computer Engineering from the U.S. Air Force Institute of Technology, and a B.S. in Computer Science from the Air Force Academy. He has 30 year of experience in the software development industry. A relatively recent arrival to the TRS-80 retro computing community, Tim tries to focus on software, but keeping his machines going has created big hardware distractions.


Title: Soldering De-mystified

Instructor: Josh Malone

Abstract: Skilled soldering is not a dark art - it’s a science! And you can learn it! Understanding the thermal and chemical details of what’s going on at the solder joint is essential to taking your soldering skills to the next level. This talk will cover detailed explanations of the processes involved in soldering and desoldering, with an emphasis on repair and re-work. Included will be discussions of irons, tip types, temperatures, solder compositions, flux, desoldering tools, and PCB construction -- everything you need to know to safely work on 30+ year-old electronics, or even modern ROHS (lead-free) boards. Even if you’ve never picked up an iron, this is your chance to get a solid foundation for learning this essential skill for a vintage computer enthusiast.

Bio: Josh Malone has been building, modding, and repairing electronics and vintage computers for over a decade. He works as a technician at his local video game arcade - when he’s not busy with his day job in I.T. - and enjoys finding all manner of odd uses for his collection of Model 100s and other “slabtops”. He tweets as @48kRAM.


Title: PocketTRS and Other Mysteries

Instructor: Arno Puder and Matt Boytim

Abstract: PocketTRS uses a modern microcontroller to emulate a TRS-80 Model III/4. It can be connected to any compatible VGA monitor and PS/2 keyboard. PocketTRS has TRS-IO embedded for full FreHD support. Among its many features is an emulation of the 50-pin expansion interface that allows to connect external peripherals. In this tech talk we will do a deep dive on the internals of PocketTRS. As an added bonus, we will also discuss an FPGA version of PocketTRS.

Bio: Arno Puder's first computer was a Videogenie that laid the foundation for a lifelong passion for everything related to ones and zeros. A few years ago he became interested in retro computing. He started a popular TRS-80 emulator for Android as well as the general purpose I/O card TRS-IO.

Matt Boytim is from Pittsburgh, PA and lives in Kokomo, IN. Matt has a BSEE from the University of Pittsburgh and an MSEE from Purdue University. Matt's first computer was a TRS-80 Model I 4k L2, which cost about 10x more than his first car.


Title: System Agnostic Debugger Frontend for the TRS-80

Instructor: Sascha Haeberling

Abstract: This talk will demonstrate a new extendable web-based TRS-80 debugger frontend that allows single-stepping Z80 instructions. It is system agnostic and thus can work with any emulator. At its core we defined a common API and protocol for TRS-80 systems to communicate with a debugger frontend. An emulator needs to only implement this interface to support our or other compatible frontends. To demonstrate the functionality, we implemented the protocol for a few well known emulators and will show it in action during this talk. And there is one more thing: Not only will we show the debugger in action for existing software emulators, we will also demonstrate a way to debug a REAL Model I!

Bio: Sascha has written software for most of his life. After finishing his Masters in Germany 14 years ago he joined Google where today he works on virtually connecting people through Project Starline. He only joined the TRS-80 community fairly recently after joining forces with Arno Puder to work on the popular TRS-80 emulator for Android. He then went on to create retrostore.org including an open API to make integration with emulators and real systems (e.g. via TRS-IO) easy.


Title: De Re CoCo

Instructor: John Linville

Abstract: This talk will present an architectural overview of the Tandy Color Computer from the programmer's perspective. There will be some coverage of the major chips (e.g. 6809, 6847, 6821) and significant peripheral features (e.g. DAC, 4-way switch, joystick ADC).

Bio: John is well known in the Tandy Color Computer community, where he is best known as the author of Fahrfall and as the most talkative member of The CoCo Crew Podcast.