We just released a Feb. 5 '89 prototype of DuckTales for the NES!
If you'd like to support our preservation efforts (and this wasn't cheap), please consider donating or supporting us on Patreon. Thank you!

Bugs:Deja Vu (NES)

From The Cutting Room Floor
Jump to navigation Jump to search

This page details bugs of Deja Vu (NES).

Music Engine Bug

Elementary, my dear Cactus.
This needs some investigation.
Discuss ideas and findings on the talk page.

A bug exists in the music engine for the triangle channel. At steady intervals, a note is dropped for certain tracks at different points while the channel plays. Shadowgate also has this bug, but it was later fixed in Uninvited. Despite the bug, the baseline for the tracks can be heard in their entirety after a couple of loops . Certain NSF files omit the first triangle note once a song starts unlike the game's sound engine.

(Source: Drag and bucky o'hare from NesDev)

Also, unknown if a bug or not, but songs will eventually loop from the very beginning if looped enough times. The game's sound composer explained that he created music for the NES using a MIDI sequencer that was converted to his sound driver. Because most of the songs use echoing through one of the channels, this causes the last note in the echo channel to overlap into the loop, something that can't be done in MIDI, so he probably copy/pasted the song a few times in the sequencer to give it a proper loop. For songs with an intro that loop at a later point in the song, this "bug" will cause the music to loop back to the very beginning.