CHIRP "unable to read"

[AC4RD]

I've got CHIRP (looks great!), got drivers for my USB-to-radio cable, everything appears to be going as expected.   I start my non-ND 817 in "clone mode" with the cable connected, use CHIRP's "download from radio" command on COM4, to get the programming I put in the radio by hand ... and after a few minutes I get an error:  "Unable to read block 00 expected 4 got 0."  COM4 is correct, AFAICT, and everything appears to work fine up until the download command.

Does anybody recognize what I'm doing wrong or what the problem might be?  TIA!

[AC5UP]

Back in the days of RS-232 serial data that would sound exactly like a buffer overflow... A speed mismatch (even a slight one) causes the receive buffer to fill within a few moments and if the handshake line can't pull CTS low the sending device won't pause long enough for the receiver can catch up. Net result is lost bits spilling out onto your desktop and dripping on your shoes. Be glad the transfer utility was smart enough to check the transfer integrity.

I'm not familiar enough with USB issues to comment any further than to suggest if there's any tweak in the transfer utility to slow down the transfer speed you should try it. Also possible you have a USB-2 port on the computer feeding a radio looking for USB-1 speeds. You might be able to tweak the USB driver to run in legacy mode or similar.

[AC4RD]

AC5UP, thanks!  I checked the COM port speed settings in 'device manager' and on the radio, couldn't make it work, did a few other things ... and I *finally* stumbled into the root of the problem: "Failure to RTFM."    Turns out after all the other steps, I needed to click "download from radio / OK" and THEN I needed to hit the "A" button on the 817 to initiate the transfer.  Works GREAT now, zero problems.

Once again it proves the wisdom of the old saying:  "When all else has failed, try actually reading the documentation."    :-)