Hardware code page

In computing, a hardware code page (HWCP) refers to a code page supported natively by a hardware device such as a display adapter or printer. The glyphs to present the characters are stored in the alphanumeric character generator's resident read-only memory (like ROM or flash) and are thus not user-changeable. They are available for use by the system without having to load any font definitions into the device first. 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.

In North American IBM-compatible PCs, the hardware code page of the display adapter is typically code page 437. However, various portable machines as well as (Eastern) European, Arabic, Middle Eastern and Asian PCs used a number of other code pages as their hardware code page, including code page 100 ("Hebrew"),151 ("Nafitha Arabic"),667 ("Mazovia"),737 ("Greek"), 850 ("Multilingual"), encodings like "Roman-8", "Kamenický", "KOI-8", "MIK", and others. Most display adapters support a single 8-bit hardware code page only. The bitmaps were often stored in an EPROM in a DIP socket. At most, the hardware code page to be activated was user-selectable via jumpers, configuration EEPROMs or CMOS setup. 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, selectable via I/O ports or additional BIOS functions.

...
Wikipedia