84PCE:Syscalls:0210E0

Synopsis

Official Name: MemSet

Syscall Address: 0210E0h

Sets a block of memory to the value in A.

Inputs

• HL: Address of memory block.
• BC: Number of bytes to zero.
• A: Value to set memory block to.

Outputs

• DE: Points to byte after memory block.

Destroys

• HL = HL+BC
• DE = HL+1+BC
• BC = 0

Comments

This routine uses an LDIR instruction to clear the memory block, so do not pass it a block length of 0 or 1 or it will erase 16777216 bytes.

See also: MemClear

Example

      ;Clear out pixelShadow with spaces
      ld     a,' '
      ld     hl,pixelShadow
      ld     bc,8400
      call   _MemSet