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ref:ymodem [2011/07/13 21:16] – digitalmanref:ymodem [2011/07/13 21:53] – digitalman
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-====== YMODEM ====== +====== XMODEM/YMODEM Protocol Reference ======
-XMODEM/YMODEM Protocol Reference+
  
 A compendium of documents describing the XMODEM and YMODEM File Transfer Protocols. A compendium of documents describing the XMODEM and YMODEM File Transfer Protocols.
  
-This document was originally edited and formatted (by Chuck Forsberg) 10-27-87. +This document was originally edited and formatted (by [[http://omen.com|Chuck Forsberg]]) 10-27-87.
- +
-This document ported to Wiki syntax by Rob Swindell July-13-2011. +
- +
- +
- +
-Please distribute as widely as possible. +
-Questions to Chuck Forsberg +
- +
- +
- +
- +
- +
-                               Omen Technology Inc +
-                          The High Reliability Software +
-                            17505-V Sauvie Island Road +
-                              Portland Oregon 97231 +
-                            VOICE: 503-621-3406 :VOICE +
-    Modem (TeleGodzilla): 503-621-3746 Speed 19200(Telebit PEP),2400,1200,300 +
-                              CompuServe: 70007,2304 +
-                                    GEnie: CAF +
-                        UUCP: ...!tektronix!reed!omen!caf+
  
 +This document was formatted for Wiki syntax by [[person:digital man|Rob Swindell]] on July-13-2011.
  
 ===== Tower of Babel ===== ===== Tower of Babel =====
Line 45: Line 24:
 Jeff Garbers (Crosstalk package development director) said it all: "With Jeff Garbers (Crosstalk package development director) said it all: "With
 protocols in the public domain, anyone who wants to dink around with them protocols in the public domain, anyone who wants to dink around with them
-can go ahead." [1]+can go ahead." ((Page C/12, PC-WEEK July 12, 1987))
  
 Documents containing altered examples derived from YMODEM.DOC have added Documents containing altered examples derived from YMODEM.DOC have added
Line 62: Line 41:
 ==== Definitions ==== ==== Definitions ====
  
-    ARC     ARC is a program that compresses one or more files into an archive +=== ARC === 
-            and extracts files from such archives.+ARC is a program that compresses one or more files into an archive 
 +and extracts files from such archives. 
 + 
 +=== XMODEM ===
  
-    XMODEM  refers to the file transfer etiquette introduced by Ward +XMODEM refers to the file transfer etiquette introduced by Ward 
-            Christensen's 1977 MODEM.ASM program.  The name XMODEM comes from +Christensen's 1977 MODEM.ASM program.  The name XMODEM comes from 
-            Keith Petersen's XMODEM.ASM program, an adaptation of MODEM.ASM +Keith Petersen's XMODEM.ASM program, an adaptation of MODEM.ASM 
-            for Remote CP/M (RCPM) systems.  It's also called the MODEM or +for Remote CP/M (RCPM) systems.  It's also called the MODEM or 
-            MODEM2 protocol.  Some who are unaware of MODEM7's unusual batch +MODEM2 protocol.  Some who are unaware of MODEM7's unusual batch 
-            file mode call it MODEM7.  Other aliases include "CP/M Users' +file mode call it MODEM7.  Other aliases include "CP/M Users' 
-            Group" and "TERM II FTP 3".  The name XMODEM caught on partly +Group" and "TERM II FTP 3".  The name XMODEM caught on partly 
-            because it is distinctive and partly because of media interest in +because it is distinctive and partly because of media interest in 
-            bulletin board and RCPM systems where it was accessed with an +bulletin board and RCPM systems where it was accessed with an 
-            "XMODEM" command.  This protocol is supported by every serious +"XMODEM" command.  This protocol is supported by every serious 
-            communications program because of its universality, simplicity, +communications program because of its universality, simplicity, 
-            and reasonable performance.+and reasonable performance.
  
-    XMODEM/CRC replaces XMODEM's 1 byte checksum with a two byte Cyclical +=== XMODEM/CRC === 
-            Redundancy Check (CRC-16), giving modern error detection +XMODEM/CRC replaces XMODEM's 1 byte checksum with a two byte Cyclical 
-            protection.+Redundancy Check (CRC-16), giving modern error detection 
 +protection.
  
-    XMODEM-1k Refers to the XMODEM/CRC protocol with 1024 byte data blocks.+=== XMODEM-1k === 
 +XMODEM-1k refers to the XMODEM/CRC protocol with 1024 byte data blocks.
  
-    YMODEM  Refers to the XMODEM/CRC (optional 1k blocks) protocol with batch +=== YMODEM === 
-            transmission as described below.  In a nutshell, YMODEM means +YMODEM refers to the XMODEM/CRC (optional 1k blocks) protocol with batch 
-            BATCH.+transmission as described below.  In a nutshell, YMODEM means 
 +BATCH.
  
-    YMODEM-g Refers to the streaming YMODEM variation described below.+=== YMODEM-g === 
 +YMODEM-g refers to the streaming YMODEM variation described below.
  
-    True YMODEM(TM) In an attempt to sort out the YMODEM Tower of Babel, Omen +=== True YMODEM(TM)=== 
-            Technology has trademarked the term True YMODEM(TM) to represent +In an attempt to sort out the YMODEM Tower of Babel, Omen 
-            the complete YMODEM protocol described in this document, including +Technology has trademarked the term True YMODEM(TM) to represent 
-            pathname, length, and modification date transmitted in block 0. +the complete YMODEM protocol described in this document, including 
-            Please contact Omen Technology about certifying programs for True +pathname, length, and modification date transmitted in block 0. 
-            YMODEM(TM) compliance.+Please contact Omen Technology about certifying programs for True 
 +YMODEM(TM) compliance.
  
-    ZMODEM  uses familiar XMODEM/CRC and YMODEM technology in a new protocol +=== ZMODEM === 
-            that provides reliability, throughput, file management, and user +ZMODEM uses familiar XMODEM/CRC and YMODEM technology in a new protocol 
-            amenities appropriate to contemporary data communications.+that provides reliability, throughput, file management, and user 
 +amenities appropriate to contemporary data communications.
  
-    ZOO     Like ARC, ZOO is a program that compresses one or more files into +=== ZOO === 
-            a "zoo archive".  ZOO supports many different operating systems +Like ARC, ZOO is a program that compresses one or more files into 
-            including Unix and VMS.+a "zoo archive".  ZOO supports many different operating systems 
 +including Unix and VMS.
                          
 ===== YMODEM Minimum Requirements ===== ===== YMODEM Minimum Requirements =====
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 receiver commands CRC-16. receiver commands CRC-16.
  
-              Figure 1.  XMODEM-1k Blocks+=== Figure 1: XMODEM-1k Blocks ===
  
-              SENDER                                  RECEIVER +      SENDER                                  RECEIVER 
-                                                      "s -k foo.bar" +                                              "s -k foo.bar" 
-              "foo.bar open x.x minutes" +      "foo.bar open x.x minutes" 
-                                                      C +                                              C 
-              STX 01 FE Data[1024] CRC CRC +      STX 01 FE Data[1024] CRC CRC 
-                                                      ACK +                                              ACK 
-              STX 02 FD Data[1024] CRC CRC +      STX 02 FD Data[1024] CRC CRC 
-                                                      ACK +                                              ACK 
-              STX 03 FC Data[1000] CPMEOF[24] CRC CRC +      STX 03 FC Data[1000] CPMEOF[24] CRC CRC 
-                                                      ACK +                                              ACK 
-              EOT +      EOT 
-                                                      ACK+                                              ACK
  
-              Figure 2.  Mixed 1024 and 128 byte Blocks+=== Figure 3: Mixed 1024 and 128 byte Blocks ===
  
-              SENDER                                  RECEIVER +      SENDER                                  RECEIVER 
-                                                      "s -k foo.bar" +                                              "s -k foo.bar" 
-              "foo.bar open x.x minutes" +      "foo.bar open x.x minutes" 
-                                                      C +                                              C 
-              STX 01 FE Data[1024] CRC CRC +      STX 01 FE Data[1024] CRC CRC 
-                                                      ACK +                                              ACK 
-              STX 02 FD Data[1024] CRC CRC +      STX 02 FD Data[1024] CRC CRC 
-                                                      ACK +                                              ACK 
-              SOH 03 FC Data[128] CRC CRC +      SOH 03 FC Data[128] CRC CRC 
-                                                      ACK +                                              ACK 
-              SOH 04 FB Data[100] CPMEOF[28] CRC CRC +      SOH 04 FB Data[100] CPMEOF[28] CRC CRC 
-                                                      ACK +                                              ACK 
-              EOT +      EOT 
-                                                      ACK+                                              ACK
  
 ===== YMODEM Batch File Transmission ===== ===== YMODEM Batch File Transmission =====
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 Only the pathname (file name) part is required for batch transfers. Only the pathname (file name) part is required for batch transfers.
  
-    To maintain upwards compatibility, all unused bytes in block 0 must be set +To maintain upwards compatibility, all unused bytes in block 0 must be set to null.
-    to null.+
  
-    Pathname The pathname (conventionally, the file name) is sent as a null +==== Pathname ==== 
-         terminated ASCII string.  This is the filename format used by the +The pathname (conventionally, the file name) is sent as a null 
-         handle oriented MSDOS(TM) functions and C library fopen functions. +terminated ASCII string.  This is the filename format used by the 
-         An assembly language example follows: +handle oriented MSDOS(TM) functions and C library fopen functions. 
-                                  DB      'foo.bar',0 +An assembly language example follows: 
-         No spaces are included in the pathname.  Normally only the file name +    DB      'foo.bar',0 
-         stem (no directory prefix) is transmitted unless the sender has +No spaces are included in the pathname.  Normally only the file name 
-         selected YAM's f option to send the full pathname.  The source drive +stem (no directory prefix) is transmitted unless the sender has 
-         (A:, B:, etc.) is not sent. +selected YAM's f option to send the full pathname.  The source drive 
- +(A:, B:, etc.) is not sent.
-Filename Considerations:+
  
 +=== Filename Considerations ===
  
   * File names are forced to lower case unless the sending system supports upper/lower case file names.  This is a convenience for       users of systems (such as Unix) which store filenames in upper and lower case.   * File names are forced to lower case unless the sending system supports upper/lower case file names.  This is a convenience for       users of systems (such as Unix) which store filenames in upper and lower case.
Line 530: Line 518:
 RZSZ.ZOO should answer other questions about YMODEM batch protocol. RZSZ.ZOO should answer other questions about YMODEM batch protocol.
  
-              Figure 3.  YMODEM Batch Transmission Session+=== Figure 3: YMODEM Batch Transmission Session ===
  
-              SENDER                                  RECEIVER +      SENDER                                  RECEIVER 
-                                                      "sb foo.*<CR>" +                                              "sb foo.*<CR>" 
-              "sending in batch mode etc." +      "sending in batch mode etc." 
-                                                      C (command:rb) +                                              C (command:rb) 
-              SOH 00 FF foo.c NUL[123] CRC CRC +      SOH 00 FF foo.c NUL[123] CRC CRC 
-                                                      ACK +                                              ACK 
-                                                      C +                                              C 
-              SOH 01 FE Data[128] CRC CRC +      SOH 01 FE Data[128] CRC CRC 
-                                                      ACK +                                              ACK 
-              SOH 03 FC Data[128] CRC CRC +      SOH 03 FC Data[128] CRC CRC 
-                                                      ACK +                                              ACK 
-              SOH 04 FB Data[100] CPMEOF[28] CRC CRC +      SOH 04 FB Data[100] CPMEOF[28] CRC CRC 
-                                                      ACK +                                              ACK 
-              EOT +      EOT 
-                                                      NAK +                                              NAK 
-              EOT +      EOT 
-                                                      ACK +                                              ACK 
-                                                      C +                                              C 
-              SOH 00 FF NUL[128] CRC CRC +      SOH 00 FF NUL[128] CRC CRC 
-                                                      ACK+                                              ACK
  
-            Figure 4.  YMODEM Batch Transmission Session-1k Blocks+=== Figure 4: YMODEM Batch Transmission Session-1k Blocks ===
  
-            SENDER                                  RECEIVER +      SENDER                                  RECEIVER 
-                                                    "sb -k foo.*<CR>" +                                              "sb -k foo.*<CR>" 
-            "sending in batch mode etc." +      "sending in batch mode etc." 
-                                                    C (command:rb) +                                              C (command:rb) 
-            SOH 00 FF foo.c NUL[123] CRC CRC +      SOH 00 FF foo.c NUL[123] CRC CRC 
-                                                    ACK +                                              ACK 
-                                                    C +                                              C 
-            STX 02 FD Data[1024] CRC CRC +      STX 02 FD Data[1024] CRC CRC 
-                                                    ACK +                                              ACK 
-            SOH 03 FC Data[128] CRC CRC +      SOH 03 FC Data[128] CRC CRC 
-                                                    ACK +                                              ACK 
-            SOH 04 FB Data[100] CPMEOF[28] CRC CRC +      SOH 04 FB Data[100] CPMEOF[28] CRC CRC 
-                                                    ACK +                                              ACK 
-            EOT +      EOT 
-                                                    NAK +                                              NAK 
-            EOT +      EOT 
-                                                    ACK +                                              ACK 
-                                                    C +                                              C 
-            SOH 00 FF NUL[128] CRC CRC +      SOH 00 FF NUL[128] CRC CRC 
-                                                    ACK+                                              ACK
  
  
  
-           Figure 5.  YMODEM Filename block transmitted by sz+=== Figure 5: YMODEM Filename block transmitted by sz === 
 +<code> 
 +      -rw-r--r--  6347 Jun 17 1984 20:34 bbcsched.txt
  
-           -rw-r--r--  6347 Jun 17 1984 20:34 bbcsched.txt +      00 0100FF62 62637363 6865642E 74787400   |...bbcsched.txt.| 
- +      10 36333437 20333331 34373432 35313320   |6347 3314742513 | 
-           00 0100FF62 62637363 6865642E 74787400   |...bbcsched.txt.| +      20 31303036 34340000 00000000 00000000   |100644..........| 
-           10 36333437 20333331 34373432 35313320   |6347 3314742513 | +      30 00000000 00000000 00000000 00000000 
-           20 31303036 34340000 00000000 00000000   |100644..........| +      40 00000000 00000000 00000000 00000000 
-           30 00000000 00000000 00000000 00000000 +      50 00000000 00000000 00000000 00000000 
-           40 00000000 00000000 00000000 00000000 +      60 00000000 00000000 00000000 00000000 
-           50 00000000 00000000 00000000 00000000 +      70 00000000 00000000 00000000 00000000 
-           60 00000000 00000000 00000000 00000000 +      80 000000CA 56 
-           70 00000000 00000000 00000000 00000000 +</code> 
-           80 000000CA 56 +=== Figure 6: YMODEM Header Information and Features ====
- +
-                Figure 6.  YMODEM Header Information and Features+
  
     _____________________________________________________________     _____________________________________________________________
Line 625: Line 613:
 ===== YMODEM-g File Transmission ===== ===== YMODEM-g File Transmission =====
  
-    Developing technology is providing phone line data transmission at ever +Developing technology is providing phone line data transmission at ever 
-    higher speeds using very specialized techniques.  These high speed modems, +higher speeds using very specialized techniques.  These high speed modems, 
-    as well as session protocols such as X.PC, provide high speed, nearly +as well as session protocols such as X.PC, provide high speed, nearly 
-    error free communications at the expense of considerably increased delay +error free communications at the expense of considerably increased delay 
-    time.+time.
  
-    This delay time is moderate compared to human interactions, but it +This delay time is moderate compared to human interactions, but it 
-    cripples the throughput of most error correcting protocols.+cripples the throughput of most error correcting protocols.
  
-    The g option to YMODEM has proven effective under these circumstances. +The g option to YMODEM has proven effective under these circumstances. 
-    The g option is driven by the receiver, which initiates the batch transfer +The g option is driven by the receiver, which initiates the batch transfer 
-    by transmitting a G instead of C.  When the sender recognizes the G, it +by transmitting a G instead of C.  When the sender recognizes the G, it 
-    bypasses the usual wait for an ACK to each transmitted block, sending +bypasses the usual wait for an ACK to each transmitted block, sending 
-    succeeding blocks at full speed, subject to XOFF/XON or other flow control +succeeding blocks at full speed, subject to XOFF/XON or other flow control 
-    exerted by the medium.+exerted by the medium.
  
-    The sender expects an inital G to initiate the transmission of a +The sender expects an inital G to initiate the transmission of a 
-    particular file, and also expects an ACK on the EOT sent at the end of +particular file, and also expects an ACK on the EOT sent at the end of 
-    each file.  This synchronization allows the receiver time to open and +each file.  This synchronization allows the receiver time to open and 
-    close files as necessary.+close files as necessary.
  
-    If an error is detected in a YMODEM-g transfer, the receiver aborts the +If an error is detected in a YMODEM-g transfer, the receiver aborts the 
-    transfer with the multiple CAN abort sequence.  The ZMODEM protocol should +transfer with the multiple CAN abort sequence.  The ZMODEM protocol should 
-    be used in applications that require both streaming throughput and error +be used in applications that require both streaming throughput and error 
-    recovery.+recovery.
  
-            Figure 7.  YMODEM-g Transmission Session+=== Figure 7: YMODEM-g Transmission Session ====
  
-            SENDER                                  RECEIVER +      SENDER                                  RECEIVER 
-                                                    "sb foo.*<CR>" +                                              "sb foo.*<CR>" 
-            "sending in batch mode etc..." +      "sending in batch mode etc..." 
-                                                    G (command:rb -g) +                                              G (command:rb -g) 
-            SOH 00 FF foo.c NUL[123] CRC CRC +      SOH 00 FF foo.c NUL[123] CRC CRC 
-                                                    G +                                              G 
-            SOH 01 FE Data[128] CRC CRC +      SOH 01 FE Data[128] CRC CRC 
-            STX 02 FD Data[1024] CRC CRC +      STX 02 FD Data[1024] CRC CRC 
-            SOH 03 FC Data[128] CRC CRC +      SOH 03 FC Data[128] CRC CRC 
-            SOH 04 FB Data[100] CPMEOF[28] CRC CRC +      SOH 04 FB Data[100] CPMEOF[28] CRC CRC 
-            EOT +      EOT 
-                                                    ACK +                                              ACK 
-                                                    G +                                              G 
-            SOH 00 FF NUL[128] CRC CRC+      SOH 00 FF NUL[128] CRC CRC
  
  
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 ==== Definitions ==== ==== Definitions ====
  
-      <soh> 01H +  <soh> 01H 
-      <eot> 04H +  <eot> 04H 
-      <ack> 06H +  <ack> 06H 
-      <nak> 15H +  <nak> 15H 
-      <can> 18H +  <can> 18H 
-      <C>   43H+  <C>   43H
  
  
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   * The last block sent is no different from others, i.e.  there is no "short block".   * The last block sent is no different from others, i.e.  there is no "short block".
    
-                  Figure 8.  XMODEM Message Block Level Protocol+=== Figure 8: XMODEM Message Block Level Protocol ===
  
     Each block of the transfer looks like:     Each block of the transfer looks like:
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 getting garbaged.  <xx> represents the checksum byte. getting garbaged.  <xx> represents the checksum byte.
  
-                  Figure 9.  Data flow including Error Recovery+=== Figure 9: Data flow including Error Recovery ===
  
     SENDER                                  RECEIVER     SENDER                                  RECEIVER
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 ==== Programming Tips ==== ==== Programming Tips ====
  
-  * The character-receive subroutine should be called with a parameter specifying the number of seconds to wait.  The receiver should first call it with a time of 10, then <nak> and try again, 10 times.+1. The character-receive subroutine should be called with a parameter specifying the number of seconds to wait.  The receiver should first call it with a time of 10, then <nak> and try again, 10 times.
  
 After receiving the <soh>, the receiver should call the character After receiving the <soh>, the receiver should call the character
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 127 characters to be seen instead of 128. 127 characters to be seen instead of 128.
  
- +2. When the receiver wishes to <nak>, it should call a "PURGE" subroutine, to wait for the line to clear.  Recall the sender tosses   any characters in its UART buffer immediately upon completing sending a block, to ensure no glitches were mis- interpreted.
-  *  When the receiver wishes to <nak>, it should call a "PURGE" subroutine, to wait for the line to clear.  Recall the sender tosses   any characters in its UART buffer immediately upon completing sending a block, to ensure no glitches were mis- interpreted.+
  
 The most common technique is for "PURGE" to call the character The most common technique is for "PURGE" to call the character
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 ensuring the other end will see it. ensuring the other end will see it.
  
-   * You may wish to add code recommended by John Mahr to your character receive routine - to set an error flag if the UART shows framing         error, or overrun.  This will help catch a few more glitches - the         most common of which is a hit in the high bits of the byte in two         consecutive bytes.  The <cksum> comes out OK since counting in 1-byte         produces the same result of adding 80H + 80H as with adding 00H + 00H.+3. You may wish to add code recommended by John Mahr to your character receive routine - to set an error flag if the UART shows framing         error, or overrun.  This will help catch a few more glitches - the         most common of which is a hit in the high bits of the byte in two         consecutive bytes.  The <cksum> comes out OK since counting in 1-byte         produces the same result of adding 80H + 80H as with adding 00H + 00H.
  
 ===== XMODEM/CRC Overview ===== ===== XMODEM/CRC Overview =====
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 protocol. A description of this handshake is presented in section 10. protocol. A description of this handshake is presented in section 10.
  
-                Figure 10.  Message Block Level Protocol, CRC mode+=== Figure 10: Message Block Level Protocol, CRC mode ===
  
     Each block of the transfer in CRC mode looks like:     Each block of the transfer in CRC mode looks like:
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 block is the coefficient of X^0 in the message polynomial. block is the coefficient of X^0 in the message polynomial.
  
-               Figure 11.  Example of CRC Calculation written in C+===Figure 11: Example of CRC Calculation written in C ===
  
-    The following XMODEM crc routine is taken from "rbsb.c".  Please refer to +The following XMODEM crc routine is taken from "rbsb.c".  Please refer to 
-    the source code for these programs (contained in RZSZ.ZOO) for usage.  A +the source code for these programs (contained in RZSZ.ZOO) for usage.  A 
-    fast table driven version is also included in this file.+fast table driven version is also included in this file.
  
 +<code>
     /* update CRC */     /* update CRC */
     unsigned short     unsigned short
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             return crc;             return crc;
     }     }
 +</code>
 ==== CRC File Level Protocol Changes ==== ==== CRC File Level Protocol Changes ====
  
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   -  the initial <C> can be garbled or lost.   -  the initial <C> can be garbled or lost.
- 
   -  the initial <soh> can be garbled.   -  the initial <soh> can be garbled.
- 
   -  the initial <C> can be changed to a <nak>.   -  the initial <C> can be changed to a <nak>.
- 
   -  the initial <nak> from a receiver which wants to receive in checksum      can be changed to a <C>.   -  the initial <nak> from a receiver which wants to receive in checksum      can be changed to a <C>.
  
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 represents the checksum byte. represents the checksum byte.
  
-          Figure 12.  Data Flow: Receiver has CRC Option, Sender Doesn't+=== Figure 12: Data Flow: Receiver has CRC Option, Sender Doesn't ===
  
     SENDER                                        RECEIVER     SENDER                                        RECEIVER
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 2 CRC bytes. 2 CRC bytes.
  
-               Figure 13.  Receiver and Sender Both have CRC Option+=== Figure 13: Receiver and Sender Both have CRC Option ===
  
     SENDER                                       RECEIVER     SENDER                                       RECEIVER
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 implement XMODEM, YMODEM, and ZMODEM with state of the art features and implement XMODEM, YMODEM, and ZMODEM with state of the art features and
 reliability. reliability.
- 
- 
-                                 LIST OF FIGURES 
- 
- 
-     Figure 1.  XMODEM-1k Blocks..........................................  11 
- 
-     Figure 2.  Mixed 1024 and 128 byte Blocks............................  11 
- 
-     Figure 3.  YMODEM Batch Transmission Session.........................  15 
- 
-     Figure 4.  YMODEM Batch Transmission Session-1k Blocks...............  15 
- 
-     Figure 5.  YMODEM Filename block transmitted by sz...................  16 
- 
-     Figure 6.  YMODEM Header Information and Features....................  16 
- 
-     Figure 7.  YMODEM-g Transmission Session.............................  17 
- 
-     Figure 8.  XMODEM Message Block Level Protocol.......................  19 
- 
-     Figure 9.  Data flow including Error Recovery........................  20 
- 
-    Figure 10.  Message Block Level Protocol, CRC mode....................  22 
- 
-    Figure 11.  Example of CRC Calculation written in C...................  23 
- 
-    Figure 12.  Data Flow: Receiver has CRC Option, Sender Doesn't........  25 
- 
-    Figure 13.  Receiver and Sender Both have CRC Option..................  26 
- 
  
 ===== See Also ===== ===== See Also =====
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 {{tag>xmodem ymodem}} {{tag>xmodem ymodem}}
 +
 +
  
  

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