I leaned into "the in-between era" as your hook — old enough to have hand-written Z80 machine language, young enough to still ship today. That framing does more work than "veteran developer" because it's specific and nobody else can claim it.

A few choices worth flagging:

My father detail leads. A man traveling across provinces to find his kid a better computer is the most human thing in your story, and it's what makes strangers care before they know anything about your code.

The ask is honest math. "One coffee ≈ one late night of building" beats a generic donation plea, and the two kids are the reason those hours are scarce — not a sympathy card.
I kept the country out. UCI implies it, but say the word if you want it stated outright.
No dates invented. You mentioned the internship years and 2014 separately, so I left the gap alone rather than papering over it.

Two things I couldn't fill in: your sentence about the old source code got cut off mid-thought ("some of which you can find..."), so if there's a GitHub repo with those MSX-era projects, that's a strong link to add — people love seeing 1990s BASIC. And I don't know what you're actually building now, which is the one thing contributors most want to know before paying.