$Id: rpc_dump.txt,v 1.1 1999/01/15 21:55:23 christ Exp $

This is the raw data that is exchanged between the Palm device and the host
when you are invoking getFeature (Trap# A27B) through RPC.
Parameters: Creator "psys" (0x70737973)
            Number: 1 
			Placeholder for Result (0x12345678)

Data sent to the device:
0000  2d 01 00 00 a2 7b 00 00 00 00 00 00 00 00 00 03   -....{..........
0010  01 04 12 34 56 78 00 02 00 01 00 04 70 73 79 73   ...4Vx......psys

Explanation:
0000: 2D 01 00 00  This always has to come first (0x2D = DLP code for dlpProcessRPC
0004: A2 7B        Trap#
0006: 00 00 00 00  D0 = 0
000A: 00 00 00 00  A0 = 0
000E: 00 03        Number of arguments
0010: 01           By Reference 
0011: 04           Length 4
0012: 12 34 56 78  Placeholder
0016: 00           Direct
0017: 02           Length 2
0018: 00 01        Parameter "Number", Value 1
001A: 00           Direct
001B: 04           Length 4
001C: 70 73 79 73  Parameter "Creator", Value 0x70737973

Note how the parameters are passed to the device in reverse order.
The function prototype is: 
Err FtrGet ( DWord creator, UInt featureNum, DWordPtr valueP)


Data received from the device:
0000  ad 01 00 00 00 00 a2 7b 00 00 00 00 00 00 f0 20   .......{.......
0010  00 03 01 04 02 05 30 00 00 02 00 01 00 04 70 73   ......0.......ps

Explanation:
0000: AD 01        This always has to come first (0xAD = 0x2D | 0x80, i.e. response to 0x2D) 
0002: 00 00        Error code = 0
0004: 00 00        Meaning unknown
0006: A2 7B        Trap#
0008: 00 00 00 00  D0 = 0
000C: 00 00 F0 20  A0 = 0x0000F020  (meaning unknown)
0010: 00 03        Number of arguments = 3
0012: 01           By Reference
0013: 04           Length = 4
0014: 02 05 30 00  Filled out placeholder (02053000)
0018: 00           Direct
0019: 02           Length = 2
001A: 00 01        Parameter "Number", Value 1
001C: 00           Direct
001D: 04           Length 4
001E: 70 73 79 73  Parameter "Creator", Value 0x70737973

Placeholder has been replaced by return value, all other parameters have been
echoed.

