This function defines a table containing default values for any pointer/data chip or single register. If default values are defined for a pointer/data chip, they must be defined for all registers within that chip.

Input

AH =

F7h
DX =
Port number:

Pointer/data chips

0h:

CRT Controller (3?4H)
8h:
Sequencer (3C4H)
10h:
Graphics Controller (3CEH)
18h:
Attribute Controller (3C0H)
Single registers

20h:

Miscellaneous Output register (3C2H)
28h:
Feature Control register (3?AH)
30h:
Graphics 1 Position register (3CCH)
38h:
Graphics 2 Position register (3CAH)
? =
B for monochrome modes, or D for color modes
ES:BX =
Points to table of one-byte entries. Each entry contains the default value for the corresponding register. The table must contain entries for all registers.

Output

AX:

Restored
BX:
Not restored
DX:
Not restored
ES:
Restored

All other registers are restored.

Example

The following example defines default values for the Attribute Controller:

attrdflt db  00h, 01h, 02h, 03h, 04h, 05h, 06h, 07h
         db  10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h
         db  08h, 00h, 0fh, 00h
         mov  ax, ds              ; assume attrdflt in data segment
         mov  es, ax              ; es = data segment
         mov  bx, offset attrdflt ; es:bx = attrdflt address
         mov  ah, 0f7h            ; f7 = define default register table
         mov  dx, 0018h           ; dx = attribute controller
         int  10h                 ; do it!

The example below defines a default value for the Feature Control register:

featdflt db  00h
         mov  ax, ds              ; assume featdflt in data segment
         mov  es, ax              ; es = data segment
         mov  bx, offset featdflt ; es:bx = featdflt address
         mov  ah, 0f7h            ; f7 = define default register table
         mov  dx, 0028h           ; dx = feature control register
         int  10h                 ; do it!

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