2.8" QD Disk Emulation
Re: 2.8" QD Disk Emulation
As near as I came time it the error comes after exactly 16 seconds.
Re: 2.8" QD Disk Emulation
~ 16 / 7.5 = ~ 2 rotations... This doesn't match with a write / check / write again / check again cycle. So i am not sure about the 2 write attempt...
Something interesting is happening i think !
Re: 2.8" QD Disk Emulation
How about this for "interesting". This is very strange...
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- Schermafbeelding 2019-09-18 om 09.10.12.png (139.63 KiB) Viewed 8631 times
Re: 2.8" QD Disk Emulation
That is the Gotek trace
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- gotektracer.jpg (234.26 KiB) Viewed 8631 times
Re: 2.8" QD Disk Emulation
It looks like during a write you need to push out the written data on the RD line, and because it doesn't see that, it retries the write and gives up after the second attempt.
Re: 2.8" QD Disk Emulation
Yes !! This is exactly what i suspected : Two Write cycle back to back without a true "verify" at all !
This is maybe a rd data line issue, but i still suspect the ready line. i will have a closer look to the traces.
Re: 2.8" QD Disk Emulation
this wr to rd bridge was mentionned some thousand of posts above but i still really hope that this is not the reason because this is quite hard if not impossible to do this with this uC... Unless he just want some random data stream...
As i said above : This thing is crazy
Re: 2.8" QD Disk Emulation
This is the gotek capture data if you need it.
http://brodgar.technology/delivery/gote ... icdata.zip
http://brodgar.technology/delivery/gote ... icdata.zip
Re: 2.8" QD Disk Emulation
thx !
one thing you may try : disconnect the RD line from the Gotek and connect it to Write data to make a loopback. Then check if the Roland does 2 writes back to back or if it try to do a really verify after the first write.
Re: 2.8" QD Disk Emulation
Two write cycles. It won't match as RD needs to be inverted from /WD.
I'll throw in an inverter to see that that does.
Re: 2.8" QD Disk Emulation
Re: 2.8" QD Disk Emulation
And btw the motor signal "glitch" at the end is maybe to clear the ready signal... i maybe forgot this...
Re: 2.8" QD Disk Emulation
No go with an inverter (just to rule that out)
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- Schermafbeelding 2019-09-18 om 10.13.48.png (139.66 KiB) Viewed 8619 times
Re: 2.8" QD Disk Emulation
Something I just remembered I wanted to check: the Reset line does go low straight after power up.
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- Schermafbeelding 2019-09-18 om 10.17.59.png (139.77 KiB) Viewed 8619 times
Re: 2.8" QD Disk Emulation
Yes. This seems to be the case with the real QD drive : MO and RY are synced at the end of the write. This is the issue.
Let me add some ASM instructions in the code