SBB_file_format
SBB (Stream of Binary Blocks)
A SBB file has one header and blocks of data to be loaded Header Format |position|field name| type|comment| |:-------|:---------|:----|:------| |0..2 |sbb_version| char(3)|always "SB" + version number (2.1=0x21)| |3..6 |machine | char(4)|ZX , CPC , MSX, 81| |7 |model | char |model 48k, +2A. 464 ...| |8..14 |extre_info| char(7)|Ready For Future Uses| |15 |ei_di | char|Enable disable interrupts between blocks| |16..31 | name | char(16)|name | |32 | locate | char|Most Significative Byte for the address of loading rutine| |33 | origin | char| sbb was built from tap, bin , sna ...| |34 | n_blocks| char|number of blocks | |35 | poke_ffff| char|msx pagination (if 0, Poke -1 is not modified)| |36..37 | clear | ushort | clear or SP (if 0, SP is not modified) | |38..39 | n_usr | ushort | execution address after loading all bloacks(if 0, it is not an executable ) |
Block format
One of this for each block |position|field name| type|comment| |:-------|:---------|:----|:------| |0..15 |blockname | char (16) | description| |16..17 |size | ushort |number of bytes for data | |18..19 |param3 | ushort | aux parammter | |20 |block_type| char| type | |21 |h_chksum | char| checksum for header of block =((ini-1) XOR jump XOR exec) | |22..23 |ini | ushort | start memory address for data | |24 |jump | char| 0xC3 or 0xCD for an executable block , 0x01 or oxc9 in other case| |25..26 |exec | ushort | execution address for block. If zero, it is not an executable block| |27 |d_chksum | char | checksum for data | |28..28+size-1|data | char (size) | memory block | .
