Hi there – There’s probably a “proper” way to do this, but here’s mine!
Id use the type tool, with a font that produces the kind of “dot” I want, then duplicate this, (right click the type layer and selecet duplicate) then go through “edit/transform/rotate 90CW” – position the verticle layer where you need it to be, then in the layers palette, merge this layer down to the layer below (it will ask you if you want to rasterize, yip) Then duplicate this new merged layer, and edit/transform/horizontal.
Hope that helps!
Scotia 😉