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Releases: jotego/jt12

PCM Refactoring

21 Dec 22:25
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PCM interpolation factored out to a different module.
PCM filter is now softer, still noticeable sound improvement

PCM interpolation

20 Dec 22:36
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YM2612 did not have internal interpolation for samples Thus, all PCM sounds not sampled at 55kHz have distortion due to spectrum duplication. This version adds a fixed x2 rate scaler for PCM samples using a CIC filter (second order, M=4). The results are very nice with much clearer samples. Bass might be too strong. I may consider compensating for bass and adding automatic sample rate detection to vary the interpolation filter rate on later releases.

Genesis Mixer

18 Dec 21:22
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-Added sound mixer for FPGAgen
-Uses JT89 with signed output
-Proper interpolation/decimation filter to interface with DAC at 54MHz

This version provides a nicer sound (cleaner and with more potent bass) because the use of filter prevents aliasing and spectrum replication inside the DAC.

Titan 2

24 Nov 07:39
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-Operator register data is updated every 12FM ticks, like YM3428. This fixes Titan 2 demo.
-Removed multiplexed output. Instead the linear output is now amplified by 1.25 to better use the dynamic range.
-Part bit (address MSB) is now latched when address write occurs (suggested by Alexey)

Better BRAM usage

19 Nov 22:03
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Changed jt12_op module. Now it doesn't resemble original logic as much, but it saves some logic cells and two M9K memory blocks in MiST implementation.

Full YM2203

15 Nov 12:28
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Full support for YM2203. Use together with JT49 tag "YM2203".

-Full operator accuracy
-Correct clock dividers
-Pipeline data stream is composed only of three channels
-YM2612 operation unchanged

YM2203

11 Nov 21:49
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YM2203 Pre-release
Pre-release

Preliminary support for YM2203. Note that frequency scaling is wrong, so songs will be played at a different pitch than the original. This will be fixed.

Scooby Doo

05 Nov 21:32
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-Phase increment width fixed
-Scooby Doo now sounds correct

CSMx1

04 Nov 17:42
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-CSM fixed
-Gain reverted to x1, as it was creating problems with at least one game ("Crying Asia Senmei Sensou")

Todos los santos

03 Nov 08:54
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-New phase and envelope generators with many bugs fixed
-No known issues at the time of release
-Minor improvement to x2 volume sound accuracy