You need to balance two competing factors when truncating a resume:
There are timeless elements to any experience you've had in life. I learned things washing dishes in a pizza kitchen as a 14 year old that still matter today in my career decades later.
Of course, when writing a resume, you want to focus on the opportunity to sell yourself for the position you're applying for. You don't want to ramble on about dishwashing as a teen when you're applying for a software development job 20 years later.
How do you balance those two things?
Firstly, my pizza kitchen job is an extreme example - but, that said, generally I don't like to see resume truncation that leaves out relevant professional positions. In your example, I would not leave those first 10 years completely out - the gap would look odd, and there's value in showing those positions, even if the direct skills are not relevant.
Dishwashing taught me basic work ethics and how to coordinate with a team. It also taught me that I didn't want to be a dishwasher for the rest of my life! I'm sure that software development and support work taught you important basic foundational elements that are still useful now that you're in to hardware. It also presumably taught you that you wanted to make a shift.
Of course, you don't want to include a ton of irrelevant detail, but putting a basic line item on your resume gives you a hook to explain more deeply as appropriate. Let's say you're interviewing for that dream hardware job, and they ask a question about how you see your career path progressing, or why you like the work you do, or some other typical "soft" question like that. Having the software positions on your resume lets you say, "well, back in the day I did this, and that made me realize X, so now I'm going in this direction."
Another important point - anyone who's been in tech for any length of time knows that trends come and go. This is true for skills, too. The "hot" platform or knowledge being sought after today may be different in 5 years. So, when hiring, I enjoy it when someone shows that they can adapt over time versus just showing off whatever key word is hot right now. In other words, including older positions - even if the skills are no longer relevant - gives you the chance to show that you can learn new things and grow over time which is more valuable in the long run than someone who's just presented as an expert in one thing.
So - in conclusion - I would definitely include those positions, but I would keep them brief. A one-sentence position description would be appropriate. Focus the bulk of your writing on the more recent, more relevant positions, but include the old ones as they're still a valuable part of your story.
