2.8" QD Disk Emulation

[Jeff]

Hi, I/O Error 3 is explained in the diagnostic section - "suspective QD" also cpu and MB89251 uSART chip

New try : Blanked/read pause added at the track beginning (track shifted and not shifted).
blanked_track_start.zip

Both ? One is a "normal" track image (not shifted), i didn't expect the error 3 with it.

EDIT : You didn't have downloaded the blanked_track_start.zip so you probably have tested the wrong files !

[Jeff]

You didn't have downloaded the blanked_track_start.zip so you probably have tested the wrong files !

viewtopic.php?f=2&t=773&start=165#p21140

[Jeff]

There is some Famicom info here, not sure if you have seen it already...
https://nesdev.com/FDS%20technical%20reference.txt

Yes sure, and i even have a FDS here, + a MO5 machine with the QD90-028. But i don't reproduce this issue with these machines...

[AMSynths]

Downloaded the correct files...but I/O Error 3 on both

[AMSynths]

Looking at the Gotek read, it does not have a pause after the Ready is asserted. Are there too many read "bits/bumps"?
Do you transmit data once the Ready signal is asserted?

[Jeff]

Downloaded the correct files...but I/O Error 3 on both

On 001 and 002 ? ok, very strange... Unless the Error 3 mean that there is a too long blank time on the serial link, which may be fine regarding the service manual notes.

[Jeff]

Looking at the Gotek read, it does not have a pause after the Ready is asserted. Are there too many read "bits/bumps"?
Do you transmit data once the Ready signal is asserted?

On the last images i post it should have a blank. Maybe it is wrongly placed ? Can you dezoom ? was 20ms/per division, now it's 200us/div

[AMSynths]

The Real QD is not sending a constant stream of data with the same number of bumps...and does not look like the "predictable" Gotek read pattern
See trace...

[Jeff]

The Real QD is not sending a constant stream of data with the same number of bumps...and does not like like the Gotek read
See trace...

Sure , this region is unformatted so the data are "random". I can add this in the image since the firmware support weak bits emulation but i am not sure if this the right way to fix the issue.

Do you see the blank part with the gotek with the 20ms per div ?

[AMSynths]

Shouldn't the Gotek data start after the Ready is asserted with a pause?
Its this early set of data which the sampler reads to check its a real QD, its failing as soon as it reads some data.

[AMSynths]

Take a look...there is no pause after Ready assert and the data looks very different.
Looks like the quick disk chip cannot sync to the data stream as its immediately throwing an error

[Jeff]

Take a look...there is no pause after Ready assert and the data looks very different.
Looks like the quick disk chip cannot sync to the data stream as its immediately throwing an error

You use 50us/div. Your screen with the blank was 20ms/div.

viewtopic.php?f=2&t=773&start=165#p21129

[AMSynths]

Here we go - Gotek Read at 20ms trace

[Jeff]

Here we go - Gotek Read at 20ms trace

With the "blanked_track_start.zip" files ?

[Jeff]

Here we go - Gotek Read at 20ms trace

With the "blanked_track_start.zip" files ?

I will check this on my gotek when i go back to home, this is quite odd.