diff --git a/historical_blobs/README.md b/historical_blobs/README.md
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+# Historical RK3588 DDR blob snapshots
+
+Extracted from the rkbin git log for cross-version analysis. v1.19 is
+the deployed version; v1.16-v1.18 are the closest-in-time prior revisions.
+
+| file | size | commit msg |
+|------|------|------------|
+| v1.16.bin | 75480 B | "update ddrbin to v1.16" — 2736 MHz LP5 dropped |
+| v1.17.bin | 73456 B | "update ddrbin to v1.17" — smaller, feature cull |
+| v1.18.bin | 75320 B | "update ddrbin to v1.18" — single-rank LPDDR5 derate crash per BUG_ANALYSIS.md |
+| v1.19     | 76704 B | current deployed (in `rkbin/bin/rk35/`) |
+
+## Byte-level divergence
+
+Each release is essentially a near-rewrite, NOT a patch:
+
+  v1.17 vs v1.18: ~88% bytes differ
+  v1.18 vs v1.19: ~88% bytes differ
+  v1.16 vs v1.19: even higher
+
+This explains why cross-version symbol porting (via Polypyus or BinDiff)
+has low yield on this target — not enough preserved byte sequences.
+Function-level fuzzy matching (i.e., reduce each function to an opcode
+silhouette with wildcards for branch targets and immediates) would help,
+but requires Ghidra-analysed baselines in each version, not just
+one-sided v1.19 annotations.
+
+## Tooling note (2026-04-15)
+
+Attempted Polypyus → blocked by Python 3.14 / pony 0.7 decompiler
+incompatibility. See `project_rk3588_ddr.md` memory for retry options
+(pyenv Python 3.11, or switch to BinDiff CLI which has no Python dep).
diff --git a/historical_blobs/SHA256SUMS b/historical_blobs/SHA256SUMS
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+++ b/historical_blobs/SHA256SUMS
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+5aa6271195e422a2c30a8e801baa64e4a10cbc6a5f1963f9a29e6dc85096c7bf  v1.16.bin
+9e0095a52febfc0f57297dff71ecc82d1686b94d47be00c21391446fc6927f7a  v1.17.bin
+d89d40a8183b099589bfcffc5cc2ce9d874eb5b1d19b78bdad2cfcf45b9cb68f  v1.18.bin
+5aa6271195e422a2c30a8e801baa64e4a10cbc6a5f1963f9a29e6dc85096c7bf  v1.16.bin
+9e0095a52febfc0f57297dff71ecc82d1686b94d47be00c21391446fc6927f7a  v1.17.bin
+d89d40a8183b099589bfcffc5cc2ce9d874eb5b1d19b78bdad2cfcf45b9cb68f  v1.18.bin
diff --git a/historical_blobs/v1.16.bin b/historical_blobs/v1.16.bin
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index 0000000..6aaaaa1
Binary files /dev/null and b/historical_blobs/v1.16.bin differ
diff --git a/historical_blobs/v1.17.bin b/historical_blobs/v1.17.bin
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index 0000000..8e597e2
Binary files /dev/null and b/historical_blobs/v1.17.bin differ
diff --git a/historical_blobs/v1.18.bin b/historical_blobs/v1.18.bin
new file mode 100644
index 0000000..0697ebd
Binary files /dev/null and b/historical_blobs/v1.18.bin differ