!
!	NAME:  MTRANS
!
!	FUNCTION:  This is the transmit module for the MacTerminal protocol
!	support on the AlphaMicro.  MRECV provides the receive support.
!	This protocol is similar to and uses the same as XMODEM protocol.  
!	First, the sender sends an escape sequence to tell the receiver to go 
!	into receive mode.  Then it sends the file information block in standard
!	XMODEM format, then an EOT.  Then XMODEM protocol is used twice, all
!	the way from the beginning NAK from the receiver to the ending
!	EOT from the sender and ACK from receiver; the first time the data
!	fork is sent; then the resource fork.
!
!	AUTHOR:  Tom Dahlquist
!
!	EDIT HISTORY:
!	  When   Who What
!	11/10/84 TAD Written (from XTRANS).
!	01/16/84 TAD Several changes.  1) Use FILEIN for input from file, thus
!			allowing us to use RUN instead of XRUN.  2) Use TIMEIN
!			for input from terminal, allowing timeouts.  3)  Ignore
!			CTL-C unless three of them hit in a row.  4) Fix little
!			bug in TRY'AGAIN.
!	01/24/85 TAD Accept either three DEL's or CTL-C's to kill us.
!	05/09/85 TAD Use CMPCRC to compute CRC.
!
!	This map is for the entire contents of one XMODEM transmission.
!	First is the SOH, then the block #, then the inverted block #,
!	then 128 data bytes, and finally the checksum.
!
	MAP1 WHOLE'BLOCK,X
		MAP2 SOH,X,1,CHR$(1)
		MAP2 BLOCK'NUMBER,B,1,1
		MAP2 NOT'BLOCK'NUMBER,B,1
		MAP2 IO'BLOCK,X,128
		MAP2 CHECK'SUM'BYTE,X,1

!
!	This is the map of the file information block sent by MacTerminal.
!	The filler byte sent after the SOH, block #, inverted block # has
!	been kept as the first byte of the block for simplicity, since the
!	AlphaMicro doesn't really care about alignment.
!
	MAP1 FILE'INFO,@IO'BLOCK
		MAP2 FILL1,X,1		! first filler byte
		MAP2 FNAME,X,64		! MacIntosh file name
		MAP2 FTYPE,S,4		! file type
		MAP2 FCREATE,S,4	! file creator
		MAP2 FFLAGS,B,2		! file flags
		MAP2 FLOC,B,4		! location in folder
		MAP2 FFOLDER,B,2	! file folder
		MAP2 LOCKED,B,2		! locked flags
		MAP2 DSIZE,X,4		! size of data fork
		MAP2 RSIZE,X,4		! size of resource fork
		MAP2 FLCRDAT,B,4	! creation date
		MAP2 FLMDDAT,B,4	! modification date
		MAP2 FILL2,X,29		! filler

	MAP1 BLOCK'LENGTH,F,,128
	MAP1 IN'CHR,X,1
	MAP1 TEST'CHR,X,1
	MAP1 OUT'CHR,X,1
	MAP1 DISK'FSPEC,S,12
	MAP1 OUT'UNIT,F,,0
	MAP1 CHECK'SUM,F
	MAP1 CTRLC,X,1,CHR$(3)
	MAP1 DEL,X,1,CHR$(255)
	MAP1 EOT,X,1,CHR$(4)
	MAP1 ACK,X,1,CHR$(6)
	MAP1 BELL,X,1,CHR$(7)
	MAP1 NAK,X,1,CHR$(21)
	MAP1 ESCAPE,X,1,CHR$(27)
	MAP1 I,F
	MAP1 NUM'BLOCKS,F
	MAP1 COUNT'BLOCKS,F
	MAP1 GOT'NAK,F
	MAP1 DEBUG,F
	MAP1 TRUE,F,,-1
	MAP1 FALSE,F,,0
	MAP1 TIMER,F
	MAP1 TEMP1,X,4
	MAP1 TEMP1X(4),X,1,@TEMP1
	MAP1 TEMP2,X,4
	MAP1 TEMP2X(4),X,1,@TEMP2
	MAP1 TEMP'SIZE,B,4,@TEMP2
	MAP1 SIZED,F
	MAP1 SIZER,F
	MAP1 SIZE,F
	MAP1 CHOICE,F
	MAP1 AREA,X,616			! for FILEIN
	MAP1 DRAIN'BUF,X,20
	MAP1 LENGTH,F			! from FILEIN and TIMEIN
	MAP1 TIMEOUT,F
	MAP1 NAK'COUNT,F
	MAP1 TIMEOUT'CNT,F
	MAP1 START'TIME,F

GET'FILENAME:
	DISK'FSPEC=""
	INPUT LINE "Name of file to be transmitted:  ",DISK'FSPEC
	IF DISK'FSPEC="" GOTO GET'FILENAME
	IF UCS(DISK'FSPEC[-2,-1])="/D" THEN &
		DISK'FSPEC=DISK'FSPEC[1,-3] : &
		OPEN #99,"MTRANS.LST",OUTPUT : &
		DEBUG=TRUE
	DISK'FSPEC=UCS(DISK'FSPEC)
	I=INSTR(1,DISK'FSPEC,".")
	IF I=0 THEN DISK'FSPEC=DISK'FSPEC+".MAC"
	LOOKUP DISK'FSPEC,I
	IF I=0 THEN &
		CALL TRY'AGAIN : &
		GOTO GET'FILENAME
	XCALL IMG
	XCALL FILEIN,1,AREA,DISK'FSPEC
!	OPEN #OUT'UNIT, "TRM:", OUTPUT
!
!	Transfer starts with sender (us) sending "ESC a" sequence to the
!	receiver, then wait for an ACK.  Then the first block is sent
!	in standard XMODEM block format.  Then we wait for an ACK.  Then
!	we send an EOT and wait for an ACK.  NOTE:  since for some
!	unfathomable reason the current version of MacTerminal (1.1) will
!	not retransmit the file information block if a NAK is received,
!	we will duplicate that behavior here.
!
	OUT'CHR=ESCAPE
	CALL SEND'ONE
	OUT'CHR="a"
	CALL SEND'ONE
	CALL WAIT'ACK
	IF GOT'NAK GOTO CLOSE'UP
	IF NOT TIMEOUT GOTO NT1
	IF DEBUG THEN &
		?#99,"Timed out waiting for ACK after header" 
	GOTO TIMEOUT
NT1:
	XCALL FILEIN,2,AREA,IO'BLOCK,LENGTH
	IF LENGTH#BLOCK'LENGTH GOTO BAD'FILE
	TIMER=TIME+2
WAIT:
	IF TIME<TIMER GOTO WAIT
	CALL SEND'BLOCK
	IF GOT'NAK GOTO CLOSE'UP
	CALL SEND'EOT
!	
!	Now we send the data and resource forks, in that order.  Each
!	fork is sent using the complete XMODEM protocol.  That means that
!	we have to first wait for a NAK from the receiver.  Then we send
!	each block as SOH, block #, inverse block #, 128 data bytes, and
!	a one byte checksum.  Then we wait for an ACK; if we get a NAK,
!	we retransmit the block.  After the last block (of each fork) we
!	send an EOT and wait for an ACK.  That's all folks!  Note one
!	little thing--the block count IS reset at the beginning of each fork.
!
	TEMP1=DSIZE
	CALL MASSAGE
	SIZED=TEMP'SIZE
	TEMP1=RSIZE
	CALL MASSAGE
	SIZER=TEMP'SIZE
	SIZE=SIZED
	CALL SEND'SEGMENT
	SIZE=SIZER
	CALL SEND'SEGMENT
	XCALL FILEIN,3,AREA
	GOTO CLOSE'UP
!
SEND'SEGMENT:
	CALL GET'ONE
	IF NOT TIMEOUT GOTO NT2
	IF DEBUG THEN &
		?#99,"Timed out waiting for NAK at beginning of fork"
	GOTO TIMEOUT
NT2:
	IF IN'CHR=CTRLC THEN &
		CALL CTRLC'ABORT : &
		GOTO SEND'SEGMENT
	IF IN'CHR=DEL THEN &
		CALL DEL'ABORT : &
		GOTO SEND'SEGMENT
	IF IN'CHR#NAK GOTO SEND'SEGMENT
	BLOCK'NUMBER=1
	NUM'BLOCKS=INT(SIZE/BLOCK'LENGTH)
	IF NUM'BLOCKS*BLOCK'LENGTH#SIZE THEN NUM'BLOCKS=NUM'BLOCKS+1
	IF NUM'BLOCKS=0 GOTO NO'DATA
	FOR COUNT'BLOCKS=1 TO NUM'BLOCKS
		XCALL FILEIN,2,AREA,IO'BLOCK,LENGTH
		IF LENGTH#BLOCK'LENGTH GOTO BAD'FILE
		NAK'COUNT=0
		TIMEOUT'CNT=0
	RETRY'BLOCK:
		CALL SEND'BLOCK
		IF GOT'NAK THEN &
			NAK'COUNT=NAK'COUNT+1 : &
			IF NAK'COUNT=5 GOTO CLOSE'UP &
			ELSE GOTO RETRY'BLOCK
		IF NOT TIMEOUT GOTO NT3
		TIMEOUT'CNT=TIMEOUT'CNT+1
		IF DEBUG THEN &
			?#99,"Timed out waiting for ACK after this block"
		IF TIMEOUT'CNT=3 GOTO TIMEOUT
		GOTO RETRY'BLOCK
	NT3:
		BLOCK'NUMBER = BLOCK'NUMBER+1
	NEXT COUNT'BLOCKS
NO'DATA:
	CALL SEND'EOT	
	RETURN

SEND'BLOCK:

	NOT'BLOCK'NUMBER=NOT BLOCK'NUMBER

	CHECK'SUM = 0
!	FOR I = 1 TO BLOCK'LENGTH
!		CHECK'SUM = CHECK'SUM+DATA'BYTES(I)
!	NEXT
!	CHECK'SUM'BYTE=CHR$(CHECK'SUM AND 255)
	XCALL CMPCRC,IO'BLOCK,CHECK'SUM'BYTE

	IF DEBUG THEN &
		?#99,STR(ASC(SOH)) : &
		?#99,STR(BLOCK'NUMBER) : &
		?#99,STR(NOT'BLOCK'NUMBER) : &
		?#99,"DATA BLOCK" : &
		?#99,STR(ASC(CHECK'SUM'BYTE))
	PRINT #OUT'UNIT,WHOLE'BLOCK;
	CALL DRAIN
	CALL WAIT'ACK
	RETURN

DRAIN:
	XCALL TIMEIN,0,DRAIN'BUF,LENGTH
	IF LENGTH=20 GOTO DRAIN
	RETURN

WAIT'ACK:
	GOT'NAK=FALSE
	CALL GET'ONE
	IF TIMEOUT RETURN
	IF IN'CHR = CTRLC THEN &
		CALL CTRLC'ABORT : &
		GOTO WAIT'ACK
	IF IN'CHR=DEL THEN &
		CALL DEL'ABORT : &
		GOTO WAIT'ACK
	IF IN'CHR = NAK THEN &
		GOT'NAK=TRUE : &
		RETURN
	IF IN'CHR <> ACK GOTO WAIT'ACK
	RETURN
	
SEND'EOT:
	OUT'CHR=EOT
	CALL SEND'ONE
	CALL WAIT'ACK
	IF GOT'NAK GOTO SEND'EOT
	IF NOT TIMEOUT RETURN
	IF DEBUG THEN &
		?#99,"Timed out waiting for ACK after EOT"
	GOTO TIMEOUT

MASSAGE:
	FOR I=1 TO 4
	TEMP2X(5-I)=TEMP1X(I)
	NEXT
	RETURN

GET'ONE:
	START'TIME=TIME
	TIMEOUT=FALSE
	XCALL TIMEIN,60,IN'CHR,LENGTH
	IF DEBUG AND LENGTH#0 THEN &
		?#99,"-";STR(ASC(IN'CHR))
	IF LENGTH=0 THEN &
		TIMEOUT=TRUE : &
		IF DEBUG THEN ?#99,"Time=";STR(TIME-START'TIME)
	RETURN

SEND'ONE:
	?#OUT'UNIT,OUT'CHR;
	IF DEBUG THEN &
		?#99,STR(ASC(OUT'CHR))
	RETURN

DEL'ABORT:
	TEST'CHR=DEL
	GOTO TEST'ABORT
CTRLC'ABORT:
	TEST'CHR=CTRLC
TEST'ABORT:
	FOR I=1 TO 2
	XCALL TIMEIN,2,IN'CHR,LENGTH
	IF LENGTH=0 OR IN'CHR#TEST'CHR RETURN
	NEXT
	?"Ending due to operator interrupt!"
	GOTO CLOSE'UP

TIMEOUT:
	?"Sorry, your Mac isn't talking to me--ending."
	GOTO CLOSE'UP

BAD'FILE:
	GOTO CLOSE'UP

CLOSE'UP:
	IF DEBUG THEN CLOSE #99
	END

!===================================================================
TRY'AGAIN:
		? "That file --- "DISK'FSPEC " --- could not be found. "
		?
		? "Would you like to: "
		? "                   1 -- Try Again! "
		? "                   2 -- Return to the Menu."
		INPUT " (enter the number of your choice ---  > ", CHOICE
		IF CHOICE=1 RETURN
		IF CHOICE#2 GOTO TRY'AGAIN
		END