[dev test] TMM27128AD — FAIL (ce5bfe529b0d)

canonical part number: AM27128A
elapsed: 30.8s

Step	Verdict	Runs	Took	Reason
id	BAD	1	3.53s	chip-ID check did not return OK
read	BAD	2	6.91s	-
blank-check	SKIPPED	1	-	Programmer error during init: Chip ID 0x303 does not match expected ID 0x189
write-partial	SKIPPED	-	-	chip-ID mismatch — destructive steps gated (chip left pristine)
verify	SKIPPED	-	-	no write target available for verify
erase	NA	-	-	-
write-baseline-b	NA	-	-	-
write-baseline-a	NA	-	-	-
sdp-lock	NA	-	-	-
write-inhibited	NA	-	-	-
sdp-unlock	NA	-	-	-
write-restored	NA	-	-	-

{
  "schema_version": "2.0",
  "generated": "2026-09-12T20:00:29Z",
  "elapsed": 30.804,
  "auto_capture": {
    "host_version": "3.0.0b39",
    "fw_board_identity": "3.0.0b27:uno",
    "hw_revision": "Rev 2.0-class",
    "chip": "AM27128A",
    "protocol": "7",
    "chip_id_expected": 393,
    "chip_id_actual": 771,
    "chip_id_mismatch_reason": null,
    "canonical_part_number": "AM27128A"
  },
  "transport_health": {
    "cobs_errors": "not measured",
    "crc_failures": "not measured",
    "decode_failures": 0,
    "probe_timeouts": 0,
    "resync_body_truncated": 0,
    "resync_length_missing": 0,
    "retries": "not measured",
    "timeouts": 0,
    "transport_suspect": false
  },
  "steps": [
    {
      "op": "id",
      "verdict": "BAD",
      "status": "COMPLETE",
      "run_count": 1,
      "reason": "chip-ID check did not return OK",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": 771,
      "duration_s": 3.529,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "read",
      "verdict": "BAD",
      "status": "COMPLETE",
      "run_count": 2,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": 6.913,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "blank-check",
      "verdict": "SKIPPED",
      "status": "COMPLETE",
      "run_count": 1,
      "reason": "Programmer error during init: Chip ID 0x303 does not match expected ID 0x189",
      "error_code": 185,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "write-partial",
      "verdict": "SKIPPED",
      "status": "SKIP",
      "run_count": 0,
      "reason": "chip-ID mismatch \u2014 destructive steps gated (chip left pristine)",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": "chip-ID mismatch \u2014 destructive steps gated (chip left pristine)"
    },
    {
      "op": "verify",
      "verdict": "SKIPPED",
      "status": "SKIP",
      "run_count": 0,
      "reason": "no write target available for verify",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "erase",
      "verdict": "NA",
      "status": "SKIP",
      "run_count": 0,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "write-baseline-b",
      "verdict": "NA",
      "status": "SKIP",
      "run_count": 0,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "write-baseline-a",
      "verdict": "NA",
      "status": "SKIP",
      "run_count": 0,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "sdp-lock",
      "verdict": "NA",
      "status": "SKIP",
      "run_count": 0,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "write-inhibited",
      "verdict": "NA",
      "status": "SKIP",
      "run_count": 0,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "sdp-unlock",
      "verdict": "NA",
      "status": "SKIP",
      "run_count": 0,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    },
    {
      "op": "write-restored",
      "verdict": "NA",
      "status": "SKIP",
      "run_count": 0,
      "reason": "",
      "error_code": null,
      "fingerprint": null,
      "fingerprint_total": null,
      "fingerprint_bad": null,
      "fingerprint_bad_pct": null,
      "fingerprint_evidence": null,
      "divergence": null,
      "chip_id_detected": null,
      "duration_s": null,
      "write_region_start": null,
      "write_region_length": null,
      "write_bits_cleared": null,
      "write_bits_retained": null,
      "write_current_source": null,
      "write_coverage": null
    }
  ],
  "banner": {
    "n_ran": 2,
    "m_applicable": 5
  },
  "voltage": {
    "vpp_before_mv": "not measured",
    "vpp_after_mv": "not measured",
    "vpe_before_mv": "not measured",
    "vpe_after_mv": "not measured"
  },
  "is_submittable": true,
  "dedup_fingerprint": "ce5bfe529b0d",
  "db_diff": {
    "current_support_status": "supported",
    "proposed_disposition": "suggests: community-fail signal (advisory -- human triage required)",
    "ladder_state": "community-fail"
  },
  "sdp_hold_state": "NOT-RUN",
  "run_status": "COMPLETE",
  "is_uv": true,
  "rail_reading_disclosure": "vpp/vpe readings measure the regulator rail only -- they do not show whether the eprom socket is connected (advisory)"
}

The physical chip tested here is a Toshiba TMM27128AD/TMM27128A (D stands for quartz window), which is not currently listed in the database.

I executed the dev test using the AM27128A profile as a close equivalent in order to generate this diagnostic report. The chip ID mismatch error is expected due to this substitution. As shown in the logs, the programmer successfully read the actual chip ID for the Toshiba part as 0x0303.

Please let me know if any further testing is needed to add the TMM27128A to the database.

@dim20

Triage — this is not an AM27128A failure, and `0x0303` is probably not an identity

Thanks for saying up front that the physical part is a Toshiba TMM27128AD and that the
AM27128A profile was a deliberate substitution, @dim20 — that saved a pointless datasheet pass
on the AMD part. Nothing here is evidence about the AM27128A entry, so no cross-check of it is
posted.

Two things to flag before this turns into a database row, though, because I think the reading
of 0x0303 may not hold.

1. The read step failed on its own, and that is the part that does not fit.

A substituted profile explains the ID mismatch completely — different part, different
signature, mismatch expected. What it does not explain is this:

Step	Verdict	Status	Runs	Gating reason
id	BAD	COMPLETE	1	— (detected `0x0303`)
read	BAD	COMPLETE	2	none — the field is empty
blank-check	SKIPPED	—	—	`Chip ID 0x303 does not match expected ID 0x189`
write-partial	SKIPPED	—	—	chip-ID mismatch — destructive steps gated
verify	SKIPPED	—	—	no write target available

The three steps the ID gate stopped say so explicitly. read does not: it ran to COMPLETE over
two runs, carries no gating reason and no recorded divergence, and still came back BAD. A
TMM27128A and an AM27128A are both 16 KB 28-pin parts on the same JEDEC 2764/27128 map, so the
substituted profile drives the identical read path. A profile substitution should have read
that chip fine. It didn't.

2. 0x0303 is the pattern this rig produces when an ID read gets nothing.

A floating or poorly-seated socket returns a distinctive not-quite-random value on the ID read
alongside bad or all-0xff data, and 0x0303 is one that has turned up before in exactly that
situation. Two further points push the same way:

There is no chip anywhere in the upstream infoic.xml database with a chip ID of
0x0303 — I checked all of it. For a real signature that would be unusual.
Signature mode is not universal on parts of this vintage. Many original 27128-class devices,
Toshiba's included, implement no electronic signature at all, in which case an ID read has
nothing to return.

Taken with the unexplained read failure, the likelier story is a seating or contact
problem, not a discovered identity. Worth re-seating the chip, checking for bent or oxidised
pins, and re-running — if read comes back OK and the ID still reads 0x0303, that is real and
this changes. If the ID moves, or read starts passing, it was the socket.

3. On adding TMM27128A to the database.

Happy to, but it cannot go in the way it might look. chip_database.json is generated from
upstream infoic.xml and is never hand-edited — a hand-added row is overwritten by the next
regeneration. And upstream has nothing to generate from here: there is no Toshiba TMM27128
record in infoic.xml at all, and no Toshiba vendor section in the generated database either.

So there are two honest routes, and neither is blocked by this issue staying open:

User override — ~/.firestarter/database.json takes a local entry and needs no upstream
change. That is the right place for it today, and it would let you test immediately.
A sourced addition to the generator — a deliberate, datasheet-backed entry, in the same
spirit as the existing correction tables that already override upstream values where upstream
is known to be wrong.

Either way, please do not let 0x0303 become the entry's chip_id until point 1 is settled.
Baking a floating-bus artefact into a database row is very hard to notice later and would make
every correctly-seated TMM27128A fail its ID check.

What would help most: the re-seat and re-run above, and — if you have it — the Toshiba
TMM27128AD datasheet, specifically whether it documents an electronic signature at all and what
VPP and program pulse width it specifies. With those, a properly sourced entry is
straightforward.

I found the actual PDF datasheet for the Toshiba TMM27128AD and as it turns out there is a twist!

You were totally right that the 0x0303 reading is a floating-bus artifact, and a quick hexdump confirmed it. The chip is completely dead and outputting nothing but 0x03 across the entire 16KB space.

However, the datasheet shows this chip does in fact have an Electronic Signature mode! I've attached it for reference.

Here are the true specs so we can add a mathematically correct row to the database for anyone else who has a working one:
Chip ID: 0x98D3 (Manufacturer 0x98, Device 0xD3).
VPP (Program): 12.5V (As is written on the chip itself).
VCC (Program): 6.0V ± 0.25V.
Pulse Width: 1.0 ms nominal (0.95 ms - 1.05 ms).

Sorry I didn't think of reading through a hexdump first! Thanks for catching the floating bus issue, this chip is going in the bin.

Toshiba TMM27128A.pdf

@dim20

That hexdump settles it — thanks for going and checking, @dim20, and for saying
so directly rather than leaving it ambiguous.

No re-test is possible or wanted here. The physical part is dead: 0x03
across the entire 16 KB is a floating bus, not data, which is also where the
0x0303 "chip ID" came from. You have binned the chip, so there is nothing left
to run. I am removing needs:report — this issue is not waiting on a report
from you, and leaving that label on would misrepresent it.

What this issue is actually worth keeping, though. Two things came out of it
that outlive the dead chip:

The part tested was a Toshiba TMM27128AD, which is not in the database at
all. It was run under the AM27128A profile, so the original FAIL was never
an AM27128A result.
Your datasheet gives real values for a row: chip ID 0x98D3
(manufacturer 0x98, device 0xD3), VPP 12.5 V, VCC (program)
6.0 V ± 0.25 V, pulse width 1.0 ms nominal (0.95–1.05 ms).

One thing to flag before anyone tries this part with a working sample. That
6.0 V programming VCC is the same wall the three Fujitsu reports hit (#66, #70,
#71) — the shield holds VCC at 5.0 V and nothing applies an elevated rail. So a
healthy TMM27128AD would very likely still fail to program, for that reason
rather than this one. Adding the database row is still worth doing; it just will
not be sufficient on its own.

Re-titling this away from AM27128A would be reasonable given the part was
never that chip.

Renamed the issue as suggested! I'll leave this open so the TMM27128AD specs can be added to the database.

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[dev test] TMM27128AD — FAIL (ce5bfe529b0d) #73

Triage — this is not an AM27128A failure, and `0x0303` is probably not an identity

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[dev test] TMM27128AD — FAIL (ce5bfe529b0d) #73

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dim20 commented on Sep 12, 2026

henols commented on Sep 16, 2026

Triage — this is not an AM27128A failure, and 0x0303 is probably not an identity

dim20 commented on Sep 16, 2026

henols commented on Sep 16, 2026

dim20 commented on Sep 16, 2026

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Triage — this is not an AM27128A failure, and `0x0303` is probably not an identity