Subfunction 00H is used to determine the size of buffer that will be necessary to contain the specified state information. The caller must supply the buffer.Saves or restores the digital-to-analog converter (DAC) state and color registers, ROM BIOS video driver data area, or video hardware state.
Call with:
AH = 1CH
AL = subfunction
00H to get state buffer size
01H to save state
02H to restore state
CX = requested states
Bit(s) Significance (if set)
0 save/restore video hardware state
1 save/restore video BIOS data area
2 save/restore video DAC state and color registers
3—15 reserved
ES:BX = segment:offset of buffer
Returns:
If function supported
AL = 1CH
and, if called with AL = 00H
BX = buffer block count (64 bytes per block)
or, if called with AL = 01H
State information placed in caller's buffer
or, if called with AL = 02H
Requested state restored according to contents of caller's buffer
Notes:
Subfunction 00H is used to determine the size of buffer that will be necessary to contain the specified state information. The caller must supply the buffer.
The current video state is altered during a save state operation (AL = 01H). If the requesting program needs to continue in the same video state, it can follow the save state request with an immediate call to restore the video state.
This function is supported on the VGA only.