Tag: Nijuu

  • TCTD Links for 2011-01-06

  • Duty Cycle Generator – Single Channel Echo

    Neil Baldwin over at Duty Cycle Generator has added the ability in his sound engine “Nijuu” to add an “echo effect” to a single square wave channel.

    Echo Demo

    How it works is to have a circular buffer (one each for voices Square 1, Square 2 & Noise) that the echo writes to by figuring out what is going to get written to the PAPU (Pseudo Audio Processing Unit) registers each frame. It then captures the register settings and continues to do so until the buffer is filled, then starts again at the beginning. When you enable echo, Nijuu retrieves the values from the buffer and writes them to the PAPU registers in the “gaps” in between notes when it decides that there’s no activity on the voice (I do this by detecting if the ADSR envelope on the voice has reached the release phase or if there is no note playing). The echo feedback continues to loop around, attenuating the captured amplitude until it reaches zero. All the while, any new notes are captured to the echo buffer in the same way and it continues to capture/attenuate/feedback notes forever until you turn it off.

    (The above quote was taken from Neil’s article and slightly modified for accuracy.)

  • Neil Baldwin #NESdev Q&A Session

    Neil Baldwin, chip music composer and director at Eurocom, dropped in for a Q&A session in #NESdev@EFnet last night for a few hours; hosted by yours truly Sean W. (a.k.a. B00daW.)  A lot of people, including Neil and I, were getting a bit “loose” to unwind during the event.  So to protect the innocent, the transcriptions below are selectively abridged.

    The evening started out with everyone discussing the differences between today’s assemblers and those of yesterday.  Assemblers are the programs that translate the assembly code to hexadecimal; the output being called “binary form” or “a binary.”  Paraphrasing what Neil had said regarding this:

    “We actually wrote our own assembler eventually.  We used it on NES and then later we added SNES support.  [The company at that point consisting of 5 people in the early 1990’s.]  We had no interactive debuggers, etc.; but it was a rudimentary IDE in as much as it was an editor with a built in assembler/disassembler.  I actually got [the old environment] compiling; but had to use DOSBox as it wouldn’t work in anything else.”

    I had asked the question if the environment would ever be available to the public to which he responded that it would have to be brought up with the other directors at Eurocom.  Perhaps we’ll get to see some of the old techniques used.  Time will tell.

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