Cisco CISCO-2501 2500 Series 2501 2-Port Serial 1-Port Ethernet AUI Router
My grandfather gave me a Cisco 2500 series router and it looks like it predates Ethernet. How can I get this working? What are all these ports, what signals do they use,
Cisco 2500 series - Wikipedia
Cisco Cisco 2501 Cisco 2500 Series Router | RecycledGoods.com