Go to the previous, next chapter.

OS/2 2.1 and beyond

OS/2 2.1 will change some aspects of font handling. First, OS/2 2.0 GA+SP has a bug that can cause OS/2 to crash when an AFM file with more than 512 kern pairs is read. This is fixed in 2.1. (This bug is separate from a design limitation in MicroSoft Windows that causes large kern tables to be read incorrectly. This problem is still under investigation; watch this space for a report.)

Fonts in 2.1 will be installed by default into the "\psfonts" directory, so that they will normally be shared with Win-OS/2 fonts. (The user will still be able to specify a directory; all that will change is the default). The user will also be able to instruct the Font Palette not to delete font files when fonts are uninstalled, so as to avoid clobbering a Win-OS/2 font by removing it from native OS/2 use through the Font Palette (although the default will still be to delete the physical font files).

OS/2 will stop using AFM files and will replace these with OFM files, a binary metrics file (different from PFM) that OS/2 will compile from the AFM file during font installation. This will speed font loading, since the system will not have to parse a plain text metrics file. Additionally, the OS/2 PostScript printer driver used to install its own, large font files, but will now use the OFM and PFB files, thereby saving 50k-200k of disk space per installed font outline.

IBM's long-term goal is to replace the 383-entity inventory of supported glyphs with Unicode. This is very much a long-term goal and there is not even a hint of when it might become available. It has its own problems, stemming from the fact that Unicode is essentially a character standard and glyph and character inventories may differ is assorted ways, but it will be a significant step in the proverbial right direction.

Excerpted from The comp.fonts FAQ, Copyright © 1992-96 by Norman Walsh