Borland Graphics Interface
The Borland Graphics Interface is a graphics library used by DOS programs, which includes the ability to use loadable drivers. These drivers have the file extension .BGI.
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Identification
Most BGI files begin with a 4-byte signature: "pk" 0x08 0x08. Note the similarity to CHR font files used by BGI.
Newer versions have an 8-byte signature: "FBGD" 0x08 0x08 0x08 0x08.
Following the signature is some text that names the driver, and gives copyright information. It usually begins with "BGI Device Driver" or "SVGA 256 Colour BGI Device Driver".
The header format was no doubt deliberately designed to be friendly to file viewers similar to the MS-DOS type command. The 0x08 bytes could be interpreted as backspace characters, which will hide the signature.
Main Entry
The first 160 bytes of the driver file are a header. This is followed by the driver code segment. Far calls will be made to this address with SI containing the function number to execute.
Related formats
Specifications
- ftp://ftp.musoftware.de/pub/uz/bgi/ contains documentation and source code for creating BGI drivers, along with several complete drivers.
