Harpsichord Tile Shifting

The Hapiscord Tile Shifting Effect is a nice way to illustrate how Ultima V manages tiles. Playing Stones on Lord British's hapiscord in Ultima V opens up the secret passage to the Sandalwood Box. However, getting out the machanism behind the vanishing of the wall gives quite amusing results.

It is important to know that all tiles of Ultima V are stored in a list. Basically, playing the hapiscord tells the game that the tile X (the wall tile in question) is to be replaced with a tile so many places down the list, which in case of the wall is a free floor. Playing the hapiscord again returns the floor to a wall, since the command now is to go an equal amout of places up the list.

Of course knowing this, the machnism can be abused in quite a number of ways, after opening the wall:
 * Pushing the potted plant into the gap and then playing Stones turns it into crendellations.
 * Pushing a southward facing chair into the gap turns it into closed portcullis.
 * Pushing a southward facing chair into the gap turns it into a table with food. Eating the food and then again playing the hapiscord turns the empty table into a mirror with reflection (it is a different tile from a normal mirror).
 * It is yet unknown, in what the Magic Carpet can turn into, after leaving it on that spot.

It must be stressed that the changing of tiles isn't anything ususual in Ultima V. It merely depends on the trigger and the number of places the tile is shifted on the tile list. This for example is used when opening the dungeons, down to profane things like walking in front of a mirror. The hapiscord is only unusual in the aspect that it can be misues to morph objects, something the programmers clearly didn't intend.

Below a video of the hapiscord effect and how it can be misused.

TXv6Lzk4ofQ The Hapiscord Effect.