Persian (Farsi) notes

Background

Microsoft introduced support for Persian (Farsi) in Windows 2000. The initial Farsi support had a number of bugs. These related to the input and dispay of the unicode character (U+06CC) ARABIC LETTER FARSI YEH. These problems have been resolved to varying degrees in Windows 2000 SP2 and subsequent releases.

The two key problems with Microsoft's implimentation of Persian (Farsi) relate to the fonts shipped with Windows 2000, and the Farsi keyboard layout in Windows 2000.

Keyboard issues

  1. Keyboard layout:
    In the initial version of the Farsi keyboard layout shipped with Windows 2000, it was not possible to type the character (U+06CC) ARABIC LETTER FARSI YEH. The key assisgned to (U+06CC) ARABIC LETTER FARSI YEH would input (U+064A) ARABIC LETTER YEH instead. This bug was fixed in Windows 2000 Service Pack 2.

  2. Keyboard layout:
    The initial fonts shipped with Windows 2000 also contained a bug relating to (U+06CC) ARABIC LETTER FARSI YEH. Letters in the Arabic script have up to four forms depending on the context of the surrounding characters. There is an isolated form (the letter by itself), an initial form (when the letter occurs at the beginning of a word), a medial form (when the letter occurs within a word), and a final form (when the letter occurs at the end of a word).

    In the unicode data on a web page all four glyphs are represented by a single unicode character. All four shapes are the same character. The font rendering system uses information in open type fonts to display the correct glyph based on the context of the character.

    The early fonts supplied by Microsoft, with Farsi support, displayed the isolated glyph instead of the medial or final glyphs of the character that were required. The Tahoma font was updated as part of Windows 2000 Service Pack 2. The other fonts were not updated by the service pack. Over time Microsoft makes changes to its fonts. Each font has a particular version number. Over time the fonts are upgraded through operating system and software upgrades.

Font issues

The following diagram shows the same text display in a older font and an updated font. You will be able to see the text displaying an incorrect glyph on the left and a correct glyph on the right. The only difference between the two images is the version of the font used to display the text.

Image of sample Persian text using older font with display bugImage of sample Persian text using corrected font

If you wish to test your fonts, please look at the text box displayed below. Does it look like the text using the correct glyph, or does it look like the text using the incorrect glyph? The test uses the following fonts: Times New Roman, Courier New and Tahoma.

خوش آمدید
خوش آمدید
خوش آمدید

If some of your fonts are displaying an incorrect glyph, it will be necessary to replace the fonts with a more recent version. Originally, updated core web fonts were available for download from Microsoft's typography web site. Microsoft decided to remove them, and they are no longer available for download.

Microsoft's EULA (End-User License Agreement) for their Core fonts for the Web allows the 'not for profit' redistribution of the fonts under specified conditions. The following fonts are available for download from the Open Road Support site:

Please read the EULA before downloading the fonts.

Tahoma needs to be updated through operating system or application upgrades. It is currently unavailable for download.

Resources

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