First of all, the font size of the system default font in DBCS PM are set to 12 point size while the SBCS OS/2 is 10 point size. If your application program creates a window with a fixed size hard-coded in your program, then you may find the text which is displayed by system default font is hidden or overlapped each other. To avoid this problem, application program must check the font to be used even if it is the system default font, after that calculate the pel size of this font from its point size with the font resolution value of the current display device.
Secondly, the dialog unit, which is used in sizing the dialog and its window control in a dialog template, depends on the system default font and display resolution. When the system default font becomes bigger, the dialog unit will also become bigger. As a result, a same dialog, that is created by a same dialog template, will have different visual size on the screen of different display device. Therefore, a big dialog which fits size in a high resolution display device may become a huge size in a lower resolution display device.
To handle this problem, when you create the dialog template by the dialog
editor utility, DLGEDIT.EXE, you make it fit to the smallest display device,
the VGA display device in DBCS OS/2 2.x version. When you create or update
the size in the source of a dialog template, please make sure that they
do not go over the size of VGA in dialog unit. The Display devices' screen
size in pel and in dialog unit shows the relationship of dialog unit and
the system default font size in each display devices. ┌──────────────────────────────────────────────────────────────────────────────┐
│ Table 2. Display devices' screen size in pel and in dialog unit
│
├───────────────────┬───────────────────┬───────────────────┬──────────────────┤
│ DISPLAY │ SCREEN SIZE IN │ SYSTEM FONT SIZE │ SCREEN SIZE IN │
│ │ PEL (RESOLUTION) │ (POINT) │ DIALOG UNIT │
├───────────────────┼───────────────────┼───────────────────┼──────────────────┤
│ PS/55 DA/2 (DBCS │ 1040x768 │ 12x24 (18) │ 346.6x256 │
│ OS/2 1.x) │ │ │ │
├───────────────────┼───────────────────┼───────────────────┼──────────────────┤
│ PS/55 DA/2 (DBCS │ 1040x768 │ 11x24 (12) │ 378x256 │
│ OS/2 2.x) │ │ │ │
├───────────────────┼───────────────────┼───────────────────┼──────────────────┤
│ XGA (DBCS OS/2 │ 1024x768 │ 11x24 (12) │ 378x256 │
│ 2.x) │ │ │ │
├───────────────────┼───────────────────┼───────────────────┼──────────────────┤
│ VGA (DBCS OS/2 │ 640x480 │ 8x18 (12) │ 320x213 │
│ 2.x) │ │ │ │
├───────────────────┼───────────────────┼───────────────────┼──────────────────┤
│ VGA (SBCS OS/2) │ 640x480 │ 6x16 (10) │ 426.7x240 │
└───────────────────┴───────────────────┴───────────────────┴──────────────────┘