> Okay, so code for missing DO low at the expected time.

Frustratingly, DO going low isn't as predictable as expected. Often/
usually it will go low after the 11th SPI write (ie the 0xFF with CS
low after the 10x8 clocks with CS high), but now I'm seeing it stay
high during that time and go low in the middle of the CMD0 bytes
following, and the file will play successfully. A file fail always happens
before this point so it's not looking possible to use DO as a reliable
indicator. If DO was reliable, then I could get the s/w to go back and
keep doing the 74 clocks again

Only a time-out trigger reliably detects inactivity

>> I'm hoping the mysterious occassional click will get fixed too
>=20
> I hope not.  Can't stand not knowing the cause of problems.  ;-)

The click is getting worse, noticeably louder and noisier and more
frequent. 3 out of 4 plays are now bad. And it plays badly in 3
distinct ways too. There's a pop, a crunch and a knock. Not in a
regular order and mixed up with good plays
=20
I'm thinking of capturing what's coming into the SPI from the card
and comparing it with the original file. I'll have to get that 512kB
SRAM board running first though

Since the first fail after 54 hours, the card is definitely getting
worse. After just a few minutes of running time since then, which
includes a lot of fails a few seconds apart that needed power
cycling, the fails are getting closer together. Several times on the
first access to the file.

The card always does the power-up initialisation though, and eg
file names are bit-bang transferred from its FAT to the 18F for
display

What I will try next is a block write after reading the FAT and
before accessing any files. Also read the card's registers so I've
something to compare with after the next format

Joe


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--=20
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