Doesn't the option to anti-alias fonts rest with the end-user of Acrobat/Adobe Reader not the originator of the pdf itself?

the problem is: if the person who will read the pdf doesn't know how to enable the option... he will see the font looking soft.

The biggest flaw of all pdfs: users!

... so, there is nothing I can do to FORCE the user, to see the pdf the way I want?

Are you sure you are using the term "antialiased", and the reverse, "make it looks not anti-aliased", correctly?
"Aliased" is jaggy, with hard edges. "Antialiased" is with constructed soft edges.

Using a pixel font, the text will (nearly) always be aliased. The "nearly" qualifier is because Acrobat also is able to antialias monochrome bitmaps of sufficiently high resolution (one can guess that to be > 1.5 x physical screen dpi).

If you have a real pixel (bitmap) font that you can use in InDesign, that will be passed on to the PDF unchanged; i.e., as pixels.

However, I'm pretty sure you cannot use real bitmap fonts in InDesign--it's way too smart to allow that. Perhaps you have a simulated pixel font instead (Press Start comes first to mind). Those fonts are vector fonts, just like anything else, and just like other vector fonts it will be antialiased for screen in Acrobat.

If you really really want a pixel font, create the text as image in Photoshop and place that into InDesign.

Alternatively, you can do it the other way around: read your InDesign created PDF into Photoshop and rasterize; then save that as PDF again.

I'm using unibody 8 ( http://www.underware.nl/site2/index.php?id1=unibody&id2=overview ).

Well, you got the idea...
=D
the font needs to look aliased, with hard edges.

The photoshop solution looks like a good one.

thanks guys.

Unibody is just a vector font, so it should look pretty much the same in the PDF as at did in InDesign. However they might be anti-aliased for screen in both Acrobat and InDesign.

Placing an image would probably be the best idea indeed.

Won't the images still be smoothed by user preference? Smooth images is a check box right next to smooth text.

I think image smoothing kicks in only with high-res pixel images. In any size large enough to read, the 'pixels' of vectorized bitmap fonts are *huge*.