The Tandy 400 is the first computer that Strong Bad used in Strong Bad Email. He had a fondness of it up until it exploded in the email "gimmick". It eventually becomes one of the antagonists for the email "retirement", sharing the position with the Compy 386.
The Tandy 400 is an old computer with green lines scrolling upward across its screen. It has a contrast knob which can adjust the greenness of said screen. After getting repaired following its explosion, the Tandy's screen has a big crack on it along with Duct tape on it's top right corner. There are also holes on its right side and top left corner.
As a ghost, the Tandy often displays a little bad graphics ghost.
At the beginning, Strong Bad used the Tandy to check emails for his series. For a while things worked fine. By an unforeseen moment, the Tandy ends up exploding while Strong Bad was checking an email. Strong Bad is saddened and has the Tandy repaired. However, he quickly starts hating the Tandy as it starts deleting emails he didn't intend to delete and saves emails that he does.
Eventually, Strong Bad gets a new computer and throws the Tandy away, where it briefly ends up in the "hands" of The King of Town. Despite this, or maybe even because of it, the Tandy makes a few returns, first appearing as a ghost in the email "ghosts" haunting Strong Badia.
Eventually, the Tandy along with its first successor, the Compy, kidnap the Lappy at some point during the email "cliffhangers". Come the next email, Strong Bad finds the three of them on top of Bubs's concession stand, with the two older computers threatening to harm the Lappy with a magnet unless Strong Bad checks one more email on them.
Strong Bad complies, but does so in a way that destroys them both permanently. In the Tandy's case, Strong Bad has Homestar pour Mountain Dew inside one of its holes while also dropping some of the King of Town's denture tablets inside, then deleting an email so hard that the Tandy explodes into pixelated oblivion. The end of the email has the Tandy and the Compy depart as ghosts.