At SHARE Pittsburgh (Aug. 16–20), attendees will have a unique opportunity to explore the roots of mainframe computing with a hands-on Assembler language bootcamp led by Geoffrey Decker, instructor at Northern Illinois University (NIU) and educator with the Eli Madison Memorial Apprenticeship (EMMA) program.
This two-hour, per day Bring Your Own Device lab (Aug. 17-20) introduces participants to core Assembler concepts using the ASSIST Assembler. It’s the first installment in a series to be held at future SHARE conferences. This offers a rare chance to build deep, practical expertise over time.
We spoke with Decker about his inspiration, approach, and why assembler still matters in modern enterprise computing.
Carrying Forward a SHARE Tradition
For Decker, the motivation behind the bootcamp is both personal and professional.
“Mostly it’s because I love the language and I love sharing it. It opens eyes!” he says. “Several of my mentors were legends at SHARE and taught assembler and MVS systems programming bootcamps. I want to carry on that tradition.”
Among his mentors were the late Dr. Robert P. Rannie, NIU professor emeritus and recipient of the SHARE John R. Ehrman Award for Sustained Excellence in Technical Education, who taught assembler and MVS systems programming at NIU for many years and also presented mainframe bootcamps on both at past SHARE conferences. Michael Stack, a fellow NIU computer science instructor, was another influential mentor. “He served as NIU's mainframe systems programmer (while NIU had its own box) and taught assembler bootcamps at SHARE alongside John R. Ehrman himself!”
Beyond passion, Decker sees a clear gap in today’s skill sets. “Software developers become better at what we do by understanding the basics of assembler, especially how it interacts with storage,” he explains.
That foundational understanding is critical for mainframe professionals working on IBM Z systems, where efficiency, performance, and resource management still matter at the deepest levels.
The "Aha" Moment: Understanding What’s Under the Hood
For attendees new to assembler, Decker promises a shift in perspective. “They’ll have a new appreciation for storage and how cool assembler really is. It’s extremely powerful and efficient,” he says.
He encourages a simple but revealing exercise: write the same program in assembler and a high-level language like C++, then compare the results. “Look at the size of the executable — and you’ll see the difference immediately,” he says.
These kinds of insights help demystify what’s happening behind the scenes in modern applications, making developers more effective across languages and platforms.
Why ASSIST Assembler?
Decker uses the ASSIST Assembler as the foundation of the bootcamp. It’s a tool he has refined over years of teaching at NIU.
According to Decker, “Using ASSIST provides a foundational learning environment. Students can read files, write records, produce storage dumps, and practice the language without too much complexity.”
The environment also introduces learners to the 24-bit addressing space of the IBM System/370, giving them a manageable entry point before advancing to more complex topics. “It gives them a strong foundation they can build on as they move into 31- and 64-bit processing and more advanced instructions,” he explains.
From Classroom to Conference: A Fast-Track Experience
While the SHARE bootcamp is based on Decker’s university and EMMA curriculum, attendees should expect a more accelerated pace. In fact, the first two parts of the bootcamp are equal to about 16 weeks of his NIU course.
Part 1 at SHARE Pittsburgh and Part 2 at a future SHARE event will cover core fundamentals, while Part 3 focuses on modern techniques and advanced assembler concepts. Participants will also gain access to real coursework.
“The same assignments my students and EMMA apprentices complete will be available,” says Decker. “I’ll also make myself available to help answer questions and debug as attendees continue learning beyond the conference.”
Why Assembler Matters
In an era of high-level languages and automation, assembler remains a critical skill in the mainframe ecosystem. “If nothing else, it will make you a better software developer,” says Decker. “You’ll understand more about what’s happening behind the scenes.”
He also points to the massive base of existing assembler code still in use today, which must be maintained and optimized. In some cases, rewriting code in assembler can deliver dramatic performance improvements.
“A former student rewrote a REXX module in assembler and cut processing time down to about 47% of what it was,” Decker recalls. For organizations focused on efficiency, performance, and legacy system optimization, those gains can be significant.
Start Your Assembler Journey at SHARE Pittsburgh
Decker encourages SHARE attendees to push past the perception that assembler is difficult. “Don’t be intimidated! Although it can be challenging, I’ll make it fun,” he says.
The bootcamp is designed to meet learners where they are, providing structured guidance, hands-on practice, and ongoing support.
The Assembler Bootcamp series at SHARE Pittsburgh is more than just a training session. It’s an opportunity to build foundational skills to elevate your mainframe career.
Whether you’re a developer, system programmer, or architect looking to deepen your technical expertise, this course offers:
- Hands-on experience with assembler fundamentals
- A structured path to advanced skills across multiple SHARE events
- Access to real coursework and instructor support
- Insights that improve performance, efficiency, and problem-solving
Just as importantly, this in-depth assembler workshop is included at no additional cost with your SHARE conference registration — a significant value compared to similar multi-day technical training courses that are often offered separately at a premium cost.
Seats are limited for this BYOD lab experience. Don’t miss your chance to learn directly from Geoffrey Decker and be part of a tradition that has shaped generations of mainframe professionals.
Register now for SHARE Pittsburgh to secure your spot in the Assembler Bootcamp and take the first step toward mastering the language that powers enterprise computing. Immediately following the conference, continue your learning with SHARE Blueprint (Aug. 20–21) and learn how to secure the mainframe in a post-quantum world.
With a BA in Music from the University of Kansas, an MS in Computer Science from Northern Illinois University and 11 years working in Kansas City as a mainframe developer in the financial industry, Geoffrey Decker has served as a faculty member of NIU's Department of Computer Science for the last 25 years. He is also a co-founder and the lead instructor for Eli Madison Memorial Apprenticeship, LLC, or EMMA. With more than 38 years of mainframe software development experience, he especially enjoys spreading the word about the IBM mainframe and the great opportunities open to new developers!