LMODEM - Xmodem written in Maclisp.

Files courtesy of Eric J. Swenson.  Published with permission from
Edward Barton.

doc/_info_/lmodem.help

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+LMODEM is a Maclisp implementation of the MODEM/XMODEM protocol that
+is often used for transferring files between microcomputer systems
+running the CP/M operating system.  It requires the MODEM program on
+the CP/M end.  (See the files MC:CPM;MODEM 206ASM, MODEM 206DOC, MODEM
+926, and MODEM DOC ; the file MBOOT ASM may also be of interest.)
+
+In order to use LMODEM you should be connected to AI, MC, or ML
+through one of the following connection paths:
+   (1) TIP connection
+   (2) Dialup (MC only)
+   (3) Connected to the machine in one of those ways and running
+       the CRTSTY program
+LMODEM cannot be used through the AI or ML dialups without modifying
+the program that runs on the CP/M end.  When LMODEM starts up it will
+tell you whether it intends to use "7-bit" or "8-bit" protocol; 7-bit
+protocol CANNOT be used without a modified CP/M MODEM program.
+
+LMODEM can deal with text (7-bit, ASCII) or binary (8-bit, "COM") files.
+You must specify what kind of file because different kinds are stored
+on ITS in different ways.  The basic usage of LMODEM is as follows:
+
+Run MODEM T on your CP/M system, connect to ITS and run LMODEM, and
+give LMODEM one of the following commands, including the parentheses:
+   (send-ascii-file "<filename>")
+   (send-com-file "<filename>")
+   (receive-ascii-file "<filename>")
+   (receive-com-file "<filename>")
+   (receive-file "<filename>")
+   (send-file "<filename>")
+(SEND means send from ITS, RECEIVE means receive onto ITS.)  Wait
+until LMODEM types the message READY; then exit the MODEM T option
+by typing whatever escape character is assembled into your MODEM
+program and (quickly) issue one of the following CP/M commands:
+    MODEM R fn.ft
+    MODEM S fn.ft
+Obviously you should use R on CP/M if you told LMODEM to SEND,
+S on CP/M if you told LMODEM to RECEIVE.  The transfer will then
+proceed, either terminating successfully or aborting due to
+excessively numerous errors or timeouts.  After the transfer
+LMODEM will await another command.
+
+(Note:  In typing a filename, the slash character "/" must be doubled.)
+
+LMODEM must adjust your ITS console and your TIP connection in a
+strange way in order to do its transfers.  If a file transfer
+terminates normally then everything will be restored, but if
+a transfer aborts then control-Z may no longer get you back to
+DDT.  If this happens you can do (RESTORE-TTY) to fix things back;
+the (QUIT) command, which kills LMODEM, will also restore things.
+If for some reason these commands fail, or you get some cryptic
+message like ;BKPT WRNG-NO-ARGS from LISP, type control-G and try
+things again.
+
+Control-L and control-K will redisplay LMODEM commands while you
+are typing them.
+
+The commands (ascii-stat "<filename>") and (com-stat "<filename>")
+can be used to print the size that a file would be on CP/M.
+
+LMODEM keeps a log file named <username> LMDLOG that tries to indicate
+what kinds of errors happen during transfers.  The file can be
+examined after you kill LMODEM with (QUIT) (or ^Z and :kill).
+In problematic cases it is also possible to find out the entire
+sequence of characters sent and received by LMODEM if a flag is
+set before the transfer; contact BUG-LMODEM if you need this.
+
+SEND-ASCII-FILE, etc. may be abbreviated as SAF, SCF, RAF, and RCF.
+
+Send mail to BUG-LMODEM at AI, ML, or MC if you have problems or
+questions.

doc/programs.md

@@ -193,6 +193,7 @@
 - LISP11, PDP-11 Lisp.
 - LIVE, PALX Game of Life.
 - LLOGO, Logo implemented in Maclisp.
+- LMODEM, Xmodem file transfer.
 - LOADP, displays system load.
 - LOCK, shut down system.
 - LOGASS, 6502 assembler in Logo.