[Coco] CoCo 2 cassette audio on emulators

[Bill Pierce]

Whatever you do, do NOT put a 16 bit wav file into VCC... it will mangle the actual file and make it unusable.
This has been a long standing bug in VCC. We hope to address this soon.
The problem with wave quality and emulators is that cassette wav images are at the exact same sample rate and freqency spcified by the Coco specs (and most likely recorded from a real Coco). This is VERY low quality. The "perfect" sound you are hearing in the real Coco while playing "audio" tapes has nothing to do with the Coco... the Coco just 'passes' the audio of recorder to the sound out. It does not process it in any way. So if the tape/player quality is bad, the sound is bad, if it is good, the sound is good... it depends on what the tape was recorded on. BUT... take a cassette recorded by a Coco and it will be low quality as the sound is single bit sound transferred to 8bit, 44khz by the (average) recorder. Put that tape on a scope and you'll find it has very little frequency range at all.
I don't think any of the emulator emulate the 'pass through' feature of the Coco "SOUNDON". VCC does not do it at all. SOUNDON actually does nothing, nor does MOTORON.
It 'should' just route the incoming sound directly to the host's sound card just as the Coco routes the sound to the sound out. It basically does the same with the cart soundout as well... Most of the emulators DO handle that part correctly or the Orch90 pak would not sound good in TV mode.

 

 


Bill Pierce
"Charlie stole the handle, and the train it won't stop going, no way to slow down!" - Ian Anderson - Jethro Tull

 

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-----Original Message-----
From: Robert Gault <robert.gault at att.net>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Sat, Jan 16, 2016 10:00 pm
Subject: Re: [Coco] CoCo 2 cassette audio on emulators

Ricardo M. Ferreira wrote:> Dear all,>> Do you know of a CoCo 2 emulator than can play cassette audio with high quality?>> Unfortunately now I don't have with me my Coco 2 (a Brazilian CP-400, actually),> so I'm using XRoar. IIRC, on the real machine I could hear on the TV the audio> from a cassette tape by typing AUDIO ON:MOTOR ON, and the quality of the audio> was "perfect" (i.e., sounding as if I had connected the cassette tape directly> to the TV audio input).>> I did a few tests on XRoar, and while data loads fine from .WAV files, music> doesn't sound very good due apparently to a low sampling rate by XRoar, no> matter the quality of the .WAV file. For example, I tried to play a 44100 Hz, 16> bit, mono sample (that sounds perfect when played on any program) using XRoar,> and it sounds like 8 bit & less than 10 kHz.>> I'm looking at XRoar's source to try to figure out if I can apply a patch, but> if someone knows about an alternative solution, I'd be glad if you could let me> know.>> Thanks!>Ricardo,Part of your problem could be the manner in which emulators process wave files. A real Coco can handle real music perfectly with AUDIO ON:MOTOR ON with the quality of the sound a function of the tape recorder.I've just done a test with MESS by taking an mp3 file and converting to a wave file. If the file is converted to 44100Hz, 8-bit, mono, it plays perfectly. Any other combination sounds awful.Try that with your XRoar.VCC will not play .wav files in this manner.Robert-- Coco mailing listCoco at maltedmedia.comhttps://pairlist5.pair.net/mailman/listinfo/coco