Related, but is there a way to emulate a VT520 on a Pi using opensource? Just want to have a replica that looks like the ultimate form of that extinct lineage.
As ex-owner of VT510, I'd say it's not really the ultimate form other than VT5xx being the last series from Digital.
For ultimate expression of Digital's VT series I'd rather go for VT340+, which supported both SIXEL and ReGIS graphics in colour. VT525 has colour graphics, but I can't find any mention of either SIXEL or ReGIS support on it.
That's "custom character support", or properly DRCS - Dynamically Redefinable Character Sets, not full SIXEL graphics.
It's essentially a way to send custom "font" to terminal. You could push it to get certain level of graphics, but it's not the same as capability of sixel bitmap.
