---NOTES ON THE PACKET RADIO MODULES FOR CP/M---


        Description of disk files.

        PACKET.ASM

        This is the main program.   It contains all the protocol logic as 
        well as the disk file I/O for both receiving and sending.


        PACIO.ASM

        This is the modem I/O module.  It has the routines which drive
        the modem as well as the stations call sign.  It needs to be
        customized for the hardware the user will be interfacing with.
        Normally it will be the only module that needs to be changed.

        RECV.ASM

        This is a very small module which provides an entry from and
        exit to CP/M for the receiver section of PACKET.ASM.

        SEND.ASM

        This  is  the same as RECV.ASM except that it causes entry to  the 
        transmitting section of PACKET.ASM.

        SEQIO2.LIB

        This is a modified version of "SEQIO.LIB" from Digital Research.
        The mods fix a bug which prevented it from working with the  RMAC 
        assembler.   It  contains the disk file interface macros and is 
        used by "PACKET.ASM" only.



              ---What to do with the above list of files---

        If you don't know what 8080 assembly language is I would  suggest 
        you  get  some help or go back to playing STARTREK  because  some 
        knowledge of this is required to modify the "PACIO.ASM" file.

        1)    Read the instructions in the "PACIO.ASM" file and modify it 
        to match your hardware.

        2)   Use the Digital Research RMAC relocating macro assembler  to 
        assemble the following files:
                       SEND.ASM
                       RECV.ASM
                       PACKET.ASM
                       PACIO.ASM





                                        1









        3)   You will now have 4 .REL files
                       SEND.REL
                       RECV.REL
                       PACKET.REL
                       PACIO.REL

             Now  you need to link them with the Digital Research  linker 
        "LINK.COM" to create two .COM files.

        Do this:  A>LINK SEND,PACIO,PACKET

                  A>LINK RECV,PACIO,PACKET

             Now  you have "SEND.COM" and "RECV.COM" which are the  ready 
        to run packet radio programs.




                 ----HOW TO USE THE SEND AND RECV PROGRAMS----

        SEND:

        First  of all there must be another station running the  RECV.COM 
        program.   Assuming  this is the case,  to send him a file do the 
        following:
                       A>SEND TEST.ASM K4ZZ

        That caused the file "TEST.ASM" to be sent to K4ZZ.

        This is the sequence of events after typing the command.

        1)  Your station and the called station are IDed in morse code in 
        the format:  HIS CALL   DE   YOUR CALL   ie:  K4ZZ DE WA4DSY.

        2)   An ENQ packet is sent to see if K4ZZ is on the air.

        3)   If an ACK packet is received from K4ZZ then Transmission  of 
        the data packets will begin.

        4)    The  file "TEST.ASM" is sent 1024 bytes per  packet.   K4ZZ 
        will send an ACK packet after each 1024 byte segment if no errors 
        are detected.   Both stations will ID in morse code after every 8 
        packets and at end of the last packet.   If K4ZZ detects an error 
        he  will send a NAK packet and your station will  retransmit  the 
        last packet up to 4 times.










                                        2









        RECV:

        There  are 2 ways to use RECV.   If you simply want to go on line 
        and  receive  all  messages or files addressed to  you  just  run 
        RECV.COM.
        example:       A>RECV

             If  you want to get a message or file from  another  station 
        just  do  the  following (assuming the other station  is  running 
        RECV.COM).

        example:       A>RECV TEST.ASM K4ZZ

             That  will  cause  K4ZZ to send you  the  TEST.ASM  file  as 
        follows.

        1)   Your station sends a file request (FRQ) packet to K4ZZ.

        2)    If K4ZZ has the file on his disk he will send an ACK and go 
        into send mode to send the file in the normal way as described in 
        the SEND section then revert to RECV again.

        3)    Your station will go into the normal receive mode  and  get 
        the packets from K4ZZ and store them on your disk.

                  *** SPECIAL CASE "DIR" *****

        If  the file name DIR is specified the directory of the disk will 
        be sent or received as if it were a file.  It will be stored in a 
        disk file named "DIR".   For example if you wondered what was  on 
        K4ZZ's  disk you would type "RECV DIR K4ZZ".   After he sends you 
        his directory you would "TYPE DIR" to see it.   You can send your 
        directory  with  the command "SEND DIR K4ZZ".   He may  not  know 
        where  it came from, since it will be stored on his disk as  "DIR" 
        with no call sign.