The Sharp CE-150 was a graphing calculator that used a pen-plotter to draw its charts. The pens haven't been manufactured in years, so Thingiverse user TeamTeamUSA is creating a 3D printable adapter that will accept modern pen cartridges:
Re-live the bygone years of RPN, 16 Kb total RAM, cassette tape storage, and plotted printing!Sharp CE-150 Printer Pen Adapter by TeamTeamUSA
A friend is a vintage computer junkie and one of his recent purchases was a printer/plotter for his Sharp PC-1500A pocket computer.
Although the printer works, the pens, being almost 30 years old, do not nor are they still available.
This is an attempt to help him re-live the geeky years of his youth!
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.