Bold default face in minibuffer-only frame

[Stefan Monnier]

I use a minibuffer-only frame and have the following setting for it:

  (setq minibuffer-frame-alist
        `((minibuffer . only)
          (top . -1) (left . 0) (user-position . t)
          (height . 1) (width . 256) (user-size . t)
          (vertical-scroll-bars . nil)
          (menu-bar-lines . 0)
          (tool-bar-lines . 0)
          ,(case window-system
             (mac '(font . "-apple-monaco-bold-*-*--12-*-*-*-*-*-*-*"))
             (t '(font . "-misc-fixed-bold-r-normal-*-13-*-*-*-*-*-*-*")))
          (background-color . "grey75")
          (name . "emacs-minibuffer")))


With the new unicode code, the default font is not bold any more, making
much more difficult to find and read.
Could someone give me hint where the problem might be?


        Stefan