[ncmncm]

One thing, there is no such thing as "DB-9". It is DE-9. The "E" is the size of the shell. (The B shell has room for 25 pins on 1/10 inch spacing, an E shell room for 9; or 15 with pins closer, as in a VGA connector.)

That fact doesn't stop retailers from listing DE-9 hardware as "DB-9" to attract confused customers, who then remain confused.

My favorite thing about these old plotters is that you can get knife pens, meant for cutting ruby-lith to send out to a circuit board fab. You would peel off the red part wherever you didn't want copper on the board. The board shop would photo-reduce your mask to actual size, often a 10x reduction for manually produced designs. Which existed!

I wonder if you can still get ruby-lith.