problem about zmodem-Record and share programming errors

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  mattdm
  protocols zmodem
  I need to include basic file-sending and file-receiving routines in my program, and it needs to be through the ZMODEM protocol. The problem is that I’m having trouble understanding the spec.For reference, here is the specification.The spec doesn’t define the various constants, so here’s a header file from Google.It seems to me like there are a lot of important things left undefined in that document:It constantly refers to ZDLE-encoding, but what is it? When exactly do I use it, and when don’t I use it? After a ZFILE data frame, the file’s metadata (filename, modify date, size, etc.) are transferred. This is followed by a ZCRCW block and then a block whose type is undefined according to the spec. The ZCRCW block allegedly contains a 16-bit CRC, but the spec doesn’t define on what data the CRC is computed. It doesn’t define the CRC polynomial it uses. I found out by chance that the CRC32 poly is the standard CRC32, but I’ve had no such luck with the CRC16 poly. Nevermind, I found it through trial and error. The CRC16 poly is 0x1021.I’ve looked around for reference code, but all I can find are unreadable, undocumented C files from the early 90s. I’ve also found this set of documents from the MSDN, but it’s painfully v

Originally posted 2013-10-17 01:49:51.