public BlockStack(final int piSize)
	{


                if(piSize != DEFAULT_SIZE)
		{
			this.acStack = new char[piSize];

			// Fill in with letters of the alphabet and keep
			// 2 free blocks
			for(int i = 0; i < piSize - 2; i++)
				this.acStack[i] = (char)('a' + i);

			this.acStack[piSize - 2] = this.acStack[piSize - 1] = '$';

			this.iTop = piSize - 3;
                        this.iSize = piSize;
		}
	}