HPDL Displays

I was fiddling with an old Logical PROMPRO-8 PROM programmer in the lab I teach in while waiting for one of the students to do something which required intervention, and noticed it had some really neat old character displays on it:

They are absolutely fucking captivating looking in person, in that “It isn’t clear what kind of light this is” sort of way, especially with the red filter lifted off so the dies are visible under the lenses. I was interested enough to closely investigate and make the unit go through some of it’s functions just to figure out what the displays are capible of, then asked the great google god to identify the design. I’m reasonably certian they are Hewlett-Packard HPDL HP-2416 displays (or one of their siblings), which are among the earliest single-die segmented LED displays, before the familiar (7- 14- or 16-) block arrangements became standard. Each package has four tiny 17 segment digits under individual epoxy bubble lenses, and an internal ASCII decoder, character generator, and memory, which should make them really fun and easy to interface. It looks like the division of HP that made the parts went to Aglilent when HP dismembered iteslf, and then was spun off as Avago with most of the other semiconductor buisness in 2005, although Litronix may have been making clones/second-source compatible parts in the 1970s as well.
…I sort of want to find some (which would mean NOS or pulls) to build a funky clock or RSS gadget or other useless status display, just to marvel at them. Sadly, it looks like that would be prohibitively expensive, as the later production drop in compatibles are “boring” 5×7 grids with similar capibilities, making originals exotic enough to be on the order of $20 a piece.