Italic versus underline in Infocom's interpreters

A patch to Frotz was offered that allows the user to have emphasized text rendered as italic rather than underline. Support for italic text was rare with earlier terminals. My wild guess is that DEC introduced it with the VT220, though I can’t find any webpages discussing this. Earlier personal computers were like this too. Later ones, particularly the Atari ST, Amiga, and Macintosh could easily do that and so Infocom games usually produced italics instead of underlines.

Curses support for italic is not part of the X/Open standard, which adds more mystery to this little nit. Can I get some feedback on what Infocom games on what hardware did italics and what did underlining?

Also what I’m wondering is if a modern Z-code interpreter, not just Frotz, should default to italic or underline when EMPHASIS_STYLE is active.


If the intention is italics, then underlining can often come across as too loud and jarring. If the intention is to underline, then italics would feel wrong in a more subtle way. So in my opinion, italics is the better default.

As an author, I find italics much more useful than underline. Italics can be used for block quotes (poems, lyrics), foreign words (a certain je ne sais quoi) and emphasis. Underline is only desirable in very specific cases, as an effect (“Do not open” says the handwritten note).


Even the 1993’s VT510 doesn’t support italics, never mind the VT220. However, italics has been listed in ECMA-48 at least since the second edition in 1979 (the first edition isn’t available online). ECMA-48 is one of those “aspirational” standards that describes all kinds of things that nobody had implemented at the time, just in case.

I can’t find a definite “added italic support” entry in the xterm or rxvt-unicode changelogs, but the first mention of “italic” in each is 2005 for xterm and 2004 for rxvt-unicode.

I’ve already written most of this on the Frotz bug report, but just to summarize:

The Macintosh, Amiga and Commodore 128 interpreters all seem to use underline. Only the Atari ST interpreter uses italic. The Apple II and DOS interpreters seem to support neither. While writing this, I realized that there would have been a C64 interpreter for some of the smaller v5 games (e.g. Border Zone). That one also seems to support neither.

Some games would print all upper case if the interpreter supported neither, but that was handled by the game, not the interpreter.

The only games I’ve found - at least so far - that seem to care about how emphasized text is drawn are Trinity and Beyond Zork, both by Brian Moriarty. The ITALICIZE routine emphasizes the whole string when running on an Atari ST (where it would use italic). Otherwise (where it would be using underline) it only emphasizes the words, not the spaces between them and not the punctuation.

Also, on Atari ST the mysterious voice you hear in Trinity has its lines written in italic without quotation marks. (Except if it’s writing the text to a transcript file, in which case the quotation marks will still be there, I think.)

Edit: The only interpreter I can personally vouch for is the Macintosh interpreter. There seems to have been at least two versions of it, because the one shipped with Border Zone was a lot faster at drawing text than the one shipped with Trinity. They both used underline tough, perhaps because of how ugly Monaco 9 italic looked?

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On the historical technicality, I must note that italics (and bold) needs a set of separate font (=more memory), when underline and reverse needed only a modified handling of the visualisation, XORing the entire character (reverse) or the last line (underline). In an era when char gen ROM was not cheap nor much large, the choices for enhancing/evidencing visuals was restricted by this. When RAM chips came by hundreds of Kbytes was possible to have a larger gamut of font style, and fonts, at an acceptable cost in resources (Amiga and Mac’s italics are created by skewing the (bitmapped…) fonts, hence the “ugliness of monaco font” noted by Andersson. (I guess he never seen Amiga’s rendition of italics…)

WARNING: “de gustibus et coloribus non est disputandum est” potential issue here: Personally, I prefer bold in evidencing what I consider important in my works.

Best regards from Italy,
dott. Piergiorgio.

You’re quite right about that. I never owned an Amiga myself, and the people I knew who did were more interested in its graphics and sound capabilities than how it rendered text, I guess. :slightly_smiling_face: