HDD (or flash) instead of a CD, questions...

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HardWareMan
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Re: HDD (or flash) instead of a CD, questions...

Post by HardWareMan » Thu Jun 29, 2017 2:51 pm

KanedaFr wrote:
HardWareMan wrote:SCOR period: 1/75 sec.
which prove MCD is 1x CD drive

and you do understand why I wanted to check fi SCOR was in sync with IRQ which 1/75sec too
Yes, but nIRQ is not 1/75. It is most like 1/150.

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Thu Jun 29, 2017 2:52 pm

HardWareMan wrote: It is quite logical. When reader detect S1 (while S0 already in internal buffer/register) it set SCOR for one subcode byte. And reset it on first non Sx subcode. It is not necessary to set it for 2.
Image
To be honest, i know the answer was on this picture...but I was unable to read it correctly :(
but still, if it read 2 frames (to get S0 & S1), it should mean SCOR should be set for 2 frames no ?

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Thu Jun 29, 2017 2:54 pm

HardWareMan wrote:
KanedaFr wrote:
HardWareMan wrote:SCOR period: 1/75 sec.
which prove MCD is 1x CD drive

and you do understand why I wanted to check fi SCOR was in sync with IRQ which 1/75sec too
Yes, but nIRQ is not 1/75. It is most like 1/150.
1/75 is what's on MCD 1 manual so it's strange.....(it's written 1 frame = 1/75s)

Image
Image

but it does not longer make sense since your capture
Image
seems to prove 1/75s seems to be the MINIMUM (MAXIMUM?) value

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Re: HDD (or flash) instead of a CD, questions...

Post by HardWareMan » Thu Jun 29, 2017 3:03 pm

KanedaFr wrote:To be honest, i know the answer was on this picture...but I was unable to read it correctly :(
but still, if it read 2 frames (to get S0 & S1), it should mean SCOR should be set for 2 frames no ?
I understand you. But the only way to find sync is get to subcode bytes with some unique states. So to sense the sync it has to store previous subcode byte. And it detect sync and set SCOR. Then comes non sync subcode byte and it take a place of S1 subcode. And S1 take place of S0. S0 is lost. Then detector reset SCOR, since it has S1 and non sync one. Simple and workable, right?

Moreover, I detected SCOR drops. But it can be because of poor CD-R quality (sometimes this game hangs...).
Image
KanedaFr wrote:seems to prove 1/75s seems to be the MINIMUM (MAXIMUM?) value
Yes, but I found 6.33ms periods that 2x shorter than required 13ms. But mostly they 13.3ms and longer.

I get it again. You was confused with this picture:
Image
SCOR uses OR and rest of scheme uses AND. But it seems to be SCOR uses AND too.

S0 and S1 both have 1xxx xxx1, and rest subcodes don't.
Image
Also, SCOR activation prove that detector have only one slot for subcode history, so it detect sync when S1 come in and ready to send out via subcode interface and S0 already stored in detector. Next subcode advance this FIFO and SCOR will be reset.

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Thu Jun 29, 2017 10:19 pm

HardWareMan wrote:...
But it seems to be SCOR uses AND too.
** FACEPALM **
Of course, the answer was here from the beginning :
SCOR is set when the synchronisation WORD is met.

This word is unique and nowhere else to be found.
But S0 BYTE could be found alone, as well as S1 BYTE but these 2 will never be met together...unless on the synchronisation WORD.

So when S0 is met, the CD DSP still don't know if it's S0 or a basic frame.
It sure it was S0 when S1 is met...and so set SCOR at that time.

Now, everything make sense.
- why I saw S0 as the 98th sector on some timings graph
- why SCOR is set when S1 is met

SCOR tells the host a new frame began and that the following frame will be the the first bit of P-W

Thanks HardWareMan !

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Re: HDD (or flash) instead of a CD, questions...

Post by HardWareMan » Fri Jun 30, 2017 3:07 am

KanedaFr wrote:SCOR tells the host a new frame began and that the following frame will be the the first bit of P-W
Yes. That is exactly what I trying to say, but from the viewpoint of probable realization in the hardware. In those days no one was to want to complicate any of IC part, because of many reasons, some of them are obvious.
KanedaFr wrote:Thanks HardWareMan !
You're welcome.

PS
One more important thing: KS9210 tell to use falling edge of FQCK to sampling S0S1:
Image
But MCD drive tell use rising edge of WFCK to sampling SCOR:
Image

PPS
Now, we can use arduino for CDC controlling, CPLD for subcode decoding to track time and syncing and some I2S DAC, such TDA1543 to build true CD player, based on MCD drive. It will be interesting, heh? CPLD also can be used for multiplexing to bytes and demultiplexing to nibbles. Somebody can say that this is overkill, but it is more free way to make any test of MCD drive. What do you say?

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Fri Jun 30, 2017 9:11 am

HardWareMan wrote: Now, we can use arduino for CDC controlling, CPLD for subcode decoding to track time and syncing and some I2S DAC, such TDA1543 to build true CD player, based on MCD drive. It will be interesting, heh? CPLD also can be used for multiplexing to bytes and demultiplexing to nibbles. Somebody can say that this is overkill, but it is more free way to make any test of MCD drive. What do you say?
Won't it be more difficult to send correct data to i2s DAC than to send serialized data from your CPLD ? (handle the data vs audio, ....)

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Fri Jun 30, 2017 9:13 am

KanedaFr wrote: What did you use to render them ?
it seems really useful to mesure time and freq as well...
Ok, I found you use the saleae software.
Did you try the i2s plugin ?

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Re: HDD (or flash) instead of a CD, questions...

Post by HardWareMan » Fri Jun 30, 2017 10:11 am

What do you want to get?

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Sun Jul 02, 2017 10:16 pm

HardWareMan wrote:What do you want to get?
OT:
nothing, only wanted to know if the I2S was as great as it seems (with sound save) ;)
I discovered the saleae products this week and they seems really good...
so bad the 16channels costs 3x the 8channels version

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Re: HDD (or flash) instead of a CD, questions...

Post by HardWareMan » Mon Jul 03, 2017 5:16 am

KanedaFr wrote:so bad the 16channels costs 3x the 8channels version
It is because 8x is only simple Cypress controller and it support only 24MS/s. 16x contain FPGA and can up to 100MS/s with 1 channel. So it is still cheaper than other LAs.

I bought for $37 (more than year ago). The cheapest LA in 16ch streaming category I bought for $69.36 (april of this year). Others with no streaming or more expensive. And one more thing: Saleae and second one bundle with very powerful and handy software. Other cheaper ones don't have it and this is decisive factor.

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Re: HDD (or flash) instead of a CD, questions...

Post by HardWareMan » Thu Jul 20, 2017 3:37 pm

It's quiet down here. Too quiet.

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Fri Jul 21, 2017 2:00 am

I was waiting for your proto ;)

I'm still on it but on the soft side : still working on a ROM tester.
My Mode1 ROM was working (until i break it yesterday), next step was to validate it on real hardware.
If it works as expected, I'll add the way to send specific command one at a time to check CDD control and validate the same result on CD and SD.

All my others posts on MCD forum is related to this project ;)

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Re: HDD (or flash) instead of a CD, questions...

Post by HardWareMan » Fri Jul 21, 2017 3:46 am

KanedaFr wrote:
Fri Jul 21, 2017 2:00 am
I was waiting for your proto ;)
Like this?
KanedaFr wrote:
Sun Jul 02, 2017 10:16 pm
nothing, only wanted to know if the I2S was as great as it seems (with sound save) ;)
I could not get him to decode I2S as a sound. Only as data.

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Re: HDD (or flash) instead of a CD, questions...

Post by KanedaFr » Fri Jul 21, 2017 2:47 pm

HardWareMan wrote:
Fri Jul 21, 2017 3:46 am
KanedaFr wrote:
Fri Jul 21, 2017 2:00 am
I was waiting for your proto ;)
Like this?
Like the one you described earlier with arduino, cpld and I2S DAC ;)

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