Just in case someone doesn't know this, you can look up any old HP part (and now Agilent) at: http://www.parts.agilent.com In some cases they will show a picture. If you lookup said part, you will find this: Part Number: 1858-0054 Description: Mod and Ser Nbr Reqd TRANSISTOR ARRAY 16-PIN PLSTC DIP Price: $10.25 Quantity on Hand: Item Status: Limited Supply - Contact Agilent Item Type: Agilent Qualified Part And, they list all products where they know it to be found.