Add description for 16 byte crostru files

1 files changed, 8 insertions, 1 deletions

diff --git a/docs/cronos-research.md b/docs/cronos-research.md
index 4cc4da0..64e2d51 100644
--- a/docs/cronos-research.md
+++ b/docs/cronos-research.md
@@ -60,7 +60,14 @@ where size can be 0xffffffff (probably to indicate a free/deleted block) some si
 large records start with plaintext: { uint32 offset, uint32 size? }
 followed by data obfuscated with 'shift==0'
 
-The old description would also assume 12 byte reference blocks but a packed struct
+If the .dat file has a version of 01.03 or later, the corresponding .tad file looks like this:
+
+    uint32_t offset
+    uint32_t size       // with flag in upper bit, 0 -> large record
+    uint32_t checksum   // but sometimes just 0x00000000, 0x00000001 or 0x00000002
+    uint32_t unknownn   // mostly 0
+
+The old description would also assume 12 byte reference blocks but a packed struct, probably if the CroFile version is 01.01.
 
     uint32_t offset1
     uint16_t size1