INT FF - PCIBM PC/FORTH - GRAPHICS API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running. Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes.
BX = function number
0001h function REDRAW
0002h function !PEL
0003h function @PEL
0004h function LINE
0005h function ARC
0006h function @BLOCK
0007h function !BLOCK
0008h function FLOOD
DS:SI -> FORTH program counter
SS:BP -> FORTH parameter stack
SS:SP -> FORTH return stack
details of parameters not available
Return: AX,BX,CX,DX,ES,DI may be destroyed
Note: these functions all display an error message if the graphics routines
are not resident