AH = D1h: Load Bitmap Data

This function loads a specified bitmap table into the next available position in the dedicated 16-KB bitmap buffer. It also pushes information about the load location, format, size, and cell dimensions onto the System Bitmap stack (BMSTK) described in "Bitmap Stack" on page 3-62. This function does not write to the Display Controller hardware. Once the data is loaded, use Int 10h, Function D3h to make it available for BitBlt operations in CGA Graphics Modes.

If the specified bitmap table is external (not built-in), then ES:SI is a pointer to the supplied bitmap table to be loaded. If this is a font (format 1 or 2), this service assumes that it is presented in the contiguous format, regardless of the requested storage format. Otherwise, the supplied bitmap table must look identical to the desired storage format. If the built-in bitmap table is also a symbol table (ID's 16,32,64,128), the format input is also ignored. The format input for font tables must be either 1 or 2.

Error conditions are identified by the state of the carry, and the value in CL.

• Input: AH = D1h
  AL = Desired Format (1,2,4,8)
  1 = Noncontiguous Font - For Display Controller in Text Modes
  2 = Contiguous Font - BitBlt
  4 = Raw Symbol Table - BitBlt No explicit char map
  8 = Mapped Symbol Table - BitBlt Includes char map
  BX = Bitmap ID (2^k; k<8 ==> Built-In)
  1 = 6x8 Font
  2 = 16x12 Font
  4 = 8x8 Font
  8 = 10x11 Font
  16,32,64,128 = Built-In symbol tables
  2^k; 8<=k<=15 = ISV/User supplied bit map tables
  CH = h (Cell Height)
  CL = w (Cell Width)
  DX = n (#Symbols)
  ES:SI = Points to bitmap structure (for ID>128)
  

• Output: CARRY CLEAR - Successful
  CARRY SET - Error
  CL: Error Code
  CL = 0 Invalid ID
  CL = 1 ID in use
  CL = 2 Bitmap Stack (BMSTK) Full
  CL = 3 Invalid Format
  CL = 4 Invalid n
  CL = 5 Bitmap Buffer Full
  

• Registers modified: AX, CL, FLAGS
• Error conditions: (See Above)