INT E0 - PCROBOTS v1.41 - "BUY_ARMOUR" - BUY OR SELL ARMOR FOR ROBOT
	AX = 001Eh
	BX = number of armor units to buy (negative to sell)
Return: nothing
Note:	each armor unit is worth 50 battery units; the robot's armor rating
	  will not go above its initial rating, so attempts to purchase more
	  will waste battery units
SeeAlso: AX=001Fh