Startup messages issued by a PC's System BIOS or displayed by an operating system before initializing its own code page switching logic and font management and before switching to graphics mode are displayed in a computer's default hardware code page.
[4] At most, the hardware code page to be activated was user-selectable via jumpers,[14] configuration EEPROMs[5][6] or CMOS setup.
[15] However, some of the display adapters designed for Eastern European, Arabic and Hebrew PCs supported multiple software-switchable hardware code pages, also named font pages,[1] selectable via I/O ports[4] or additional BIOS functions.
They can be selected via DIP switches or configuration menus on the printer, or via specific escape sequences.
[28][29] However, OEM code pages do not necessarily reside in ROM, but include so called prepared code pages,[2][25] (aka downloadable character sets or downloadable fonts), character sets loaded as raster fonts into the font RAM of suitable display adapters (like Sirius 1/Victor 9000,[30] NEC APC,[31] HP 100LX/200LX/700LX,[15] Persyst's BoB Color Adapter,[32] Hercules' HGC+,[33][13][34] InColor[33][35] and Network Plus[36][37] with RAMFONT, and IBM's MCGA,[33][38][13] EGA,[38][13] VGA,[38][13] etc.)