Source : Free On-Line Dictionary of Computing

ZMODEM
     
         A file transfer protocol with error checking and
        crash recovery.  Developed by Chuck Forsberg.  Its transfer
        rate is similar to {YMODEM-g}.  Like YMODEM-g, ZMODEM does not
        wait for positive acknowledgement after each block is sent,
        but rather sends blocks in rapid succession.  If a ZMODEM
        transfer is cancelled or interrupted for any reason, the
        transfer can be resurrected later and the previously
        transferred information need not be resent.
     
        {FTP Oakland
        (ftp://oak.oakland.edu/pub/simtelnet/msdos/zmodem/)}, {FTP PDX
        (ftp://ftp.cs.pdx.edu/pub/zmodem/)}.
     
        Telephone: +1 900 737 7836.
     
        (1996-07-02)