Where was the biggest department store which IBM Printer Model 4 headquartered? 
IBM Printer Model 4:  It and its successor, the IBM 4610, are still used by retailers such as El Corte Inglés, Publix, Zara, and Ripley. El Corte Inglés: El Corte Inglés S.A., headquartered in Madrid, is the biggest department store group in Europe and ranks fourth worldwide.
Madrid