What do you mean those were the days? I use this pretty much every day at work. c$ etc are default shares that appear if you turn on File and Printer sharing. The NTFS ACLs default to read if you are an authenticated user (RW for local admins) and the share ACL is probably local admins only (domain admins get that by default). So, \\machine_name\c$\tmp works exactly as I need it to on say Windows server 2016.
File sharing defaults into disabled nowadays, and it will only accept users authenticated on the same domain as the computer. It used to default into enabled, and grant read access to anonymous users.
