I hope that you will consider making condensed versions of DejaVu Mono Sans.
By condensed I mean a font that is darker (thicker lines), but narrower (approx 75% wide---what I really would like is 15-pitch).
At the moment I used a modified version of the PovRay Crystal font (the original, not the current one), since that is the right width--but it has a non-standard encoding and a v. limited range of characters and no bold or italic. My prime use of the font is in computer textbooks.
I think DejaVu Mono Sans is already too condensed. It was hard to implement some letters using existed metrics of Mono Sans.
Mono Sans is “Standard” width: it is sized so that when set 10/12 each glyph is a 2×1 rectangle. Matching wide glyphs are then a perfect square when set 10/12.
Most monowidth fonts fit that pattern.
Knuth, et al’s Computer Modern Typewriter is a notable exception. Luc(as) de Groot’s Thesis Mono also has, as I recall, a narrow version. Both were designed for setting code in books, where the page width is more narrow.
A narrow version of DejaVu Sans Mono would not be a bad idea, but it would probably be more useful as a cubic-spline font, since it would be used most for paper publishing.
I tried converting the existing Mono fonts using the narrow.pe script, but using
86 rather than 90 as the scaling factor. This produces the right size (from a book point of view). But as James Cloos noted, what is needed is a 2x1 shape.
Would it be possible to have a book.pe script that could do this?
Then all I'd need to do is fix the - (copy the + and get rid of the |) and the Q (which is too close to O, needs the tail to enter the circle), and I'd have a usable monospaced font for books.
The narrow font version does not need to be 2×1, nor should it be.
CMTT10 has a width of 525 units in a 1000 unit em (a 2×1 ratio at 10/12 translates to 600 units), so it is 87.5% as wide as typical mono fonts.
If you want to stick with TTF (and its typical 2048 unit em), I'd target a width of 1075 and play with narrow.pe until I got that result. (1072 and 1080 may also be interesting options.)
But note that narrow.pe really generates condensed fonts. With PostScript you can get the same result just by changing the font matrix. A proper narrow font will keep the stem widths — or condense them only a bit — of the normal-width version.
Unfortunately, I'm not a typopgrapher, so I don't know the details of _how_ to get what I want. But I do typeset computer text books, so I do know _what_ I want.
Basically I need a condensed mono typeface (roman and italic, and a bold that is distinct from roman, but as "weak" as possible while being distinct).
I don't need or want TrueType since I use the lout typesetting tool which works best with PostScript Type1. But I don't know how to do "changing the font matrix".
Anyway, I'll try to find a font that is designed as mono/condensed and that has distinct 1lL and O0Q.
Mark: Have you looked at the M+ fonts?
Although they are japanese fonts M+ 1m, 1mn and 2m are Mono fonts with ASCII characters. They are condensed and come in various weights (thin, light, regular, medium and bold). Do they fit your needs?
I've now looked at the M+ fonts, and some of them are of a suitable width, such as 1m, 1mn, and 2m. However, James Cloos has now produced a narrow version of DejaVu Sans Mono that is almost perfect. (I just had to do two changes: copy + to - and delete the | so that + and - have identical crossbars, and make the tail of the Q enter the Q's circle so that Q, O, and 0, are distinct.) I will be using my derivative of James' in future.