Toshiba PDR-M4 Protocol Description Notes
by Chris Douglass (cjd03246@pegasus.cc.ucf.edu)

History:
Created 1/8/2000 by Chris Douglass (cjd03246@pegasus.cc.ucf.edu)
Modified 1/20/2000 by Chris Douglass

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Notes
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I used ComLite32 to sniff the com port on win98. It is available at http://www.rtcomm.com.
The camera Camera generally uses 4-byte words to communicate. 
Least significant byte is transferred first.
The camera usually echoes back the first 2 bytes of the command it is responding to.
Many commands take a 4-byte argument.

A question mark in the command name notes that I am not too sure about it's purpose.

The camera's beacon is 0x88 0x8f. It sends this until it recieves the reset code.

The first two bytes are the actual command, the second two bytes is the length of
the command's argument; same with respone codes

Actaul commands are in stars
-------------------------------------
Commands (All commands listed in hex)
-------------------------------------
Set Baud Rate:			
	*31 05* 04 00, XX 00 00 00
		where 04 00 is the argument length and
		      XX 00 00 00 is the baud rate code:
			XX	Baud Rate
			01	9600
			02	19200
			03	38400
			04	57600
			05	115200
			
	Expected response: 31 05 00 00
	Comments: This is the first command sent to detect and initialize the camera.
		  It is also used as a cancel command to stop a file transfer and
		  to close communications at the end of a session.


Get Directory info sync status:
	*10 00* 00 00
	Expected responses:
		No change since last reset: 10 00 00 00
		Directory info changed:	    10 89 00 00
		possibly more

Get Folder List:
	*14 00* 00 00
	Expected response:
		14 00 AA AA, [XX XX 10 00, YY YY 10 00, ....]
			Where AA AA is the number of folders * 4 (actually the number of 			bytes in the reply) and XX XX and YY YY are the folder numbers. 
			(AA AA)/4 folder numbers are sent. Presumably if AA AA is zero
			then there are no folder numbers to send.

Get folder/file information:
	*15 00* 04 00, XX XX YY YY 
		where XX XX is the folder number and YY YY is the file number.
		If YY YY is zero then a list of files in this filder is returned.
	Expected Response for file list (YY YY == 00 00):
		15 00 AA AA, [XX XX 00 00, YY YY 00, ....]
			Where AA AA is the number of files * 4 (actually the number of 				bytes in the reply) and XX XX and YY YY are the file numbers. 
			(AA AA)/4 file numbers are sent. If AA AA is zero
			then no folder numbers are sent.
	Expected Response for file information (YY YY is set to the file number):
		15 00 14 00, "PDRM", "????", "JPG ", XX XX XX XX, YY YY YY YY
			15 00  -- seems to mean "file exist, sending data"
			14 00  -- length of reply (20 bytes)
			"PRDM" -- the camera's signature ont he filename?
			"????" -- This is the picture number in ASCII
			"JPG " -- Note the trailing space to fill 4 bytes
			       -- Just a Format String, PNG someday?
			XX XX XX XX -- Timestamp
			YY YY YY YY -- File size


Set output block size:
	*30 05* 04 00, 00 08 00 00
		where 04 00 is the argument length and
		      00 08 is the buffer size
	Expected Response: 30 05 00 00
	Comments: This is sent after the directory information has been retrieved. Then
		  the directory info is retrieved again.

Get file sync status?: 
	*20 00* 00 00 
	Expected Responst: 20 CA 00 00
	Comments: This is sent just after "Reset for File Transfer Mode?" I don't know what
		  it does.
 
Send data:
	*17 00* AA AA, XX XX YY YY, ZZ ZZ ZZ ZZ
		where AA AA is the number of bytes to send
		      XX XX is the directory number.
		      YY YY is the file number.
		      ZZ ZZ ZZ ZZ is the offset into the file from which to start sending.
	Expected Response: 17 00 AA AA, (AA AA) bytes of data
		where AA AA is the number of bytes of data to follow

Delete file:
	*43 05* 04 00, XX XX YY YY
		where 04 00 is the length of the argument
		      XX XX is the directory number
		      YY YY is the file number
	Expected Response: 43 05 00 00


-----------------
Transfer Sequence
-----------------
Set Baud Rate
Get Status
if changed {
	get folder list
	for i=1 to (number of folders) {
		get file/folder info for folder i, file 00 00
		for j=1 to (number of files in folder i) {
			get file/folder info for folder x, file j
		} end for j
	} end for i
} end if changed
Set output buffer size?
Set baud rate
Get file sync status?
Get Status
if changed {
	get folder list
	for i=1 to (number of folders) {
		get file/folder info for folder i, file 00 00
		for j=1 to (number of files in folder i) {
			get file/folder info for folder x, file j
		} end for j
	} end for i
} end if changed

	
delete files
Set baud rate
drop DTR