The samples use a female voice and are "one" "two" "three" "four" "hi (or hai)" "good" "next" and "hello, let's go". This chip can store eight speech samples within 960 bytes of ROM space. It only used this chip for Family Trainer 3: Aerobics Studio in February of 1987, one of the ten games it released for the Japanese version of the NES Power Pad (the Family Trainer Mat). In this case, Bandai used a crude speech synthesis chip called the Mitsubishi M50805. Nintendo never released a peripheral that used the NES expansion port, so NES games never used the expansion audio functionality.īandai appears to be the first cartridge hardware maker to use hardware to allow a cartridge to generate on-board audio. However, this pin must be bridged with a resistor to an unused pin on the cartridge connector to mix the audio. There is a pin on the expansion connector on the NES front loader by which a cartridge can send its audio to be mixed with the audio from the NES's APU. Instead, the NES sends its audio directly to the RF & AV unit. While the NES has the same internal audio as the Famicom, it does not send its audio to the cartridge connector. The 2A03 outputs the pulse channels on one pin and the triangle, noise and DPCM channels on another pin and they are mixed on the console's PCB and then sent to the cartridge connector. The fifth channel can play back digitized samples with 7-bit fidelity typically using delta modulation but it can also output 7-bit samples directly.
The pulse and noise channels have a 4-bit volume control. The pulse channels can apply sweeps to the frequency and both the pulse and noise channels can have ASDR envelopes applied to them. The short sequence was not available until 2A03 revision E CPUs, which were used after Nintendo had been manufacturing Famicoms for about a year. The long sequence typically sounds something like white noise and is often used for sound effects or percussion.
#Famicom studybox generator
The fourth channel is a noise generator with sixteen frequency selections and short and long sequences. It is typically used for rhythm and usually sounds rather mellow.
The third channel is a triangle wave generator with a 32-step waveform (16 steps up, 16 steps down) and an 11-bit frequency divider. The two channels have equal functionality. They are frequently used as the main instruments in APU music, but sound somewhat hollow. The three aurally distinct choices have the duty cycle at 50%, 25% and 12.5%, which can be visualized in the following manner (one period) : The variable duty cycles feature makes these channels more flexible than the ordinary square wave channels found on the TI SN76489 used on the Sega Master System. The first two channels produce pulse wave generators with variable duty cycles (three effective choices) with 11-bit frequency divider. The APU can produce five channels of music. Inside the NES and Famicom's CPU chip, the 2A03 or 2A07, there exists an Audio Processing Unit. In this article, let's take a look at the methods that were used and the games that used them.įirst, we must consider the features of the internal audio. 26 (of 1,054) licensed Famicom games contained hardware that could produce additional music and mix it in with the internal audio. For most games, the audio was sent back to the system without modification. The Famicom always sent its internal audio to the cartridge port. The Famicom was constructed with a feature which was not available to the NES.
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