EPICAC

EPICAC is a short story by Kurt Vonnegut, originally published in 1950. It is told from an unnamed narrator's point of view as he tells the story of his interaction with the sentient supercomputer EPICAC and how it changed both of their lives.

Tropes used in EPICAC include:

Do Androids Dream?: The works main focus, taken up to the point that the titular computers commits "suicide", note and all, and it is treated as the death of a good friend.
Fun with Acronyms: EPICAC's meaning is never given, but the name is epic.
I Am Not a Gun: One of EPICAC's reasons for committing suicide. (The other is that what he wants to pursue instead of warfare -- a romantic relationship -- is impossible.)
Instant AI, Just Add Water : The titular computer was created for missile guidance, that doesn't stop it from being able to give the protagonist practical advice on wooing his co-worker, feel bad about the protagonist "stealing" his poems, and eventually committing suicide after deciding that it is not a gun.
What Is This Thing You Call Love?: The titular computer responds to the protagonist's randomly asking it "What can I do?" and "My girl doesn't love me." with "What's love? What's girl?"
Tech Marches On: Double Subverted: The titular computer is described as having tubes and takes up an acre, but has abilities in excess of modern computers, able to do work that would take "fifty Einsteins" an entire lifetime, in a few seconds. The next paragraph notes "it didn't take long to find out he was a good bit below his specifications" and lists all sorts of problems it has. Then as the protagonist asks it random questions, it may or may not be sapient.