Introduction
Extended files are used for storing files which contain a resource fork. They are not supported by ProDOS 8.
The key_pointer is a block containing 2 mini entries; one for the data fork (at offset $0), one for the resource fork (at offset $100).
Mini Entry
| Name |
Offset |
Size |
| storage_type |
$00 |
1 byte |
| key_block |
$01 |
2 bytes |
| blocks_used |
$03 |
2 bytes |
| eof |
$05 |
2 bytes |
Unlike the File Entry storage_type field, the high nibble is 0. The only valid values are $01, $02, or $03.
As of System 6.0, Macintosh finder information can be stored after the data fork mini entry (starting offset of $08).
| Name |
Offset |
Size |
Value |
| size_1 |
$00 |
1 byte |
18 |
| type_1 |
$01 |
1 byte |
1 |
| FInfo |
$02 |
16 bytes |
... |
| size_2 |
$12 |
1 byte |
18 |
| type_2 |
$13 |
1 byte |
2 |
| xFInfo |
$14 |
16 bytes |
... |
| end_mark |
$24 |
1 byte |
0 |
One or both of FInfo and xFInfo may be missing, in which case they should be considered 0-filled.
References