84PCE:Syscalls:0210DC

Synopsis

Official Name: MemClear

Syscall Address: 0210DCh

Sets a block of memory to zero.

Inputs

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

Outputs

• DE: Points to byte after memory block.

Destroys

• A = 0
• 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: MemSet

Example

      ;Clear out pixelShadow
      ld     hl,pixelShadow
      ld     bc,8400
      call   _MemClear