diff --git a/z80_unpacker/readme.txt b/z80_unpacker/readme.txt
index b7fff1b..4d93ac9 100644
--- a/z80_unpacker/readme.txt
+++ b/z80_unpacker/readme.txt
@@ -10,10 +10,23 @@ may be incompatible with files you will produce with current version)
 
 Asm syntax is z00m's sjasmplus: https://github.com/z00m128/sjasmplus
 
+Backward direction unpacker added as compile-time option, see example for both forward/backward
+depacker in action.
+
+The packed/unpacked data-overlap has to be tested per-case, in worst case the packed data
+may need even more than 7 bytes to unpack final byte, but usually 1-4 bytes may suffice.
+
 TODO:
-- build base corpus of test data to benchmark future changes in algorithm/format
-- review first implementation to identify weak spots where the implementation can be shorter+faster
-with acceptable small changes to the format
-- review non-bitstream variant, if it's feasible to try to implement it with Z80
+- build bigger corpus of test data to benchmark future changes in algorithm/format (example and zx48.rom was used to do initial tests)
+- maybe try to beat double-loop `decode_number` with different encoding format
 - (@ped7g) Z80N version of unpacker for ZX Next devs
 - (@exoticorn) add Z80 specific packer (to avoid confusion with original MicroW8 variant), and land it all to master branch, maybe in "z80" directory or something? (and overall decide how to organise+merge this upstream into main repo)
+- (@exoticorn) add to packer output with possible packed/unpacked region overlap
+
+DONE:
+* review non-bitstream variant, if it's feasible to try to implement it with Z80
+    - Ped7g: IMHO nope, the 12b x 8b MUL code would probably quickly cancel any gains from the simpler state update
+* review first implementation to identify weak spots where the implementation can be shorter+faster
+with acceptable small changes to the format
+    - Ped7g: the decode_bit settled down and now doesn't feel so confused and redundant, the code seems pretty on point to me, no obvious simplification from format change
+    - Ped7g: the decode_number double-loop is surprisingly resilient, especially in terms of code size I failed to beat it, speed wise only negligible gains
diff --git a/z80_unpacker/unpack.asm b/z80_unpacker/unpack.asm
index e0218e9..637b048 100644
--- a/z80_unpacker/unpack.asm
+++ b/z80_unpacker/unpack.asm
@@ -4,7 +4,7 @@
 ;; initial version by Peter "Ped" Helcmanovsky (C) 2022, licensed same as upkr project ("unlicensed")
 ;; to assemble use z00m's sjasmplus: https://github.com/z00m128/sjasmplus
 ;;
-;; you can define UPKR_PROBS_ORIGIN to specific 256 byte aligned address for probs array (386 bytes),
+;; you can define UPKR_PROBS_ORIGIN to specific 256 byte aligned address for probs array (320 bytes),
 ;; otherwise it will be positioned after the unpacker code (256 aligned)
 ;;
 ;; public API: