Topic       : TOS - das Betriebssystem
Author      : 
Version     : tos.hyp (5. März 2013)
Subject     : Programmieren/Atari
Nodes       : 3001
Index Size  : 93602
HCP-Version : 5
Compiled on : Atari
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View Ref-File15.13.2.2  Message group 2                                         TOS

ACC_META = 0x503
ACC_IMG  = 0x504

These message are used to exchange drawings and pictures. Only the 
file formats defined in the GEM documentation are used; they are 
sufficient to meet most requirements, and any GEM application should 
be able to handle them anyway.

  1. Sending a metafile:

          msg[0]:  ACC_META (0x503)
          msg[3]:  1 for the final part, 0 otherwise
          msg[4] und msg[5]:   pointer to data
          msg[6] und msg[7]:   length of data (32 bit longword)

     The metafile data is sent in the same format as they would be 
     stored on disk. As metafiles can become quite large and 
     especially accessories often do not have sufficient memory to 
     store them, a file can be sent in several pieces. The receiver 
     has to take care of assembling all parts to restore the original 
     data, if neccessary by writing the parts to a file. The last part 
     of a file is marked by msg[3]=1. The sender may send no other 
     data between the parts of a file. msg[6] and msg[7] contain the 
     length of the part being sent, not the total length.

     The receiver acknowledges each part as described for level 1. As 
     for text messages, the sender must make sure that the data to be 
     transferred is stored in globally accessible memory.

  2. Sending a bit image file:

     msg[0]: ACC_IMG (0x504)

     otherwise identical to 1.