[time-nuts] HP 53131A - reset security code

Wed Dec 24 02:33:07 UTC 2014

I'm the seller. The counters, as a matter of interest, came from the
factory that Rakon recently closed in Lincoln. Unfortunately there wasn't
any contact with the actual staff so I have no information about them.

I bought 3, kept one for myself - the only one with the MS option. I
haven't tried the cal procedure yet so I'm not sure if mine is locked, but
I do have the gear to sniff the eeprom bus so will do that if needed.

Only one thing - two of the counters were HP branded, one was Agilent. I
think the Agilent had later firmware and that's the one that went to
Ulli.   I meant to copy the ROMs before I sent it but forgot, so I may have
different firmware to him. Not sure if that will affect the EEPROM content.

One thing that occurs to me is that car radios of this era had security
codes in them to deter theft. It was generally held that if you lost the
code, putting them in the freezer would temporarily corrupt the codes long
enough to force them back to reset. Maybe something similar would work -
though it's likely that all the other cals would be cleared too. The
trigger thresholds probably aren't too hard, but would the interpolator be
calibrated too ?

On Wed, Dec 24, 2014 at 1:55 AM, Richard Solomon <w1ksz at earthlink.net>
wrote:

> Is there some reason you cannot just ask Agilent ??
>
> 73 es HH, Dick, W1KSZ
>
>
>
> On 12/23/2014 6:34 PM, Tom Van Baak wrote:
>
>> Ulli,
>>
>> You're right. The actual procedure is not described in the manual(s):
>>
>> Operating Guide
>> http://cp.literature.agilent.com/litweb/pdf/53131-90055.pdf
>>
>> Programming Guide
>> http://cp.literature.agilent.com/litweb/pdf/53131-90044.pdf
>>
>> Assembly-Level Service Guide
>> http://cp.literature.agilent.com/litweb/pdf/53131-90039.pdf
>>
>> Component Level Information
>> http://literature.cdn.keysight.com/litweb/pdf/5989-6308EN.pdf
>>
>> But I have three ides for you.
>>
>> 1) The last PDF shows U14 is AT28C64B (www.atmel.com/Images/doc0001h.pdf)
>> so if all else fails, you can use a logic analyzer on the address(13) /
>> data(8) pins and see what's in the EEPROM. With some experimentation by you
>> or others on the list we can locate the calibration security. This has the
>> advantage of getting the existing code, without having to clear the entire
>> EEPROM. Some other HP bench instruments use an onboard jumper to override
>> the cal lock, but I don't see that on a 53131A. So perhaps there is a magic
>> front panel sequence or SCPI command to clear NVRAM.
>>
>> 2) Search for 53132 at http://www.ko4bb.com/manuals/index.php and grab
>> the 4 EPROM's. Do a 16-bit merge of U8/U10 and U9/U11 and look for ascii
>> strings. All the SCPI words are in there and not all are documented. For
>> example near the words SYST and CODE and SEC[URITY] is ALL and DEL[ETE].
>> Probably safe to try. Lots of interesting output strings, both for GPIB and
>> for internal debugging. Even the words EEPROM CLEAR, along with "Oooh! That
>> tickles. I don't know that vector." which we also see in the Z3801A, etc.
>>
>> There's also a hidden "SERVICE MENU", complete with Easter egg:
>>     MLB TEAM KRISTI BITTNER, LEE COSART, ERIC INGMAN, GARY JACOBSEN,
>> SOOK-LAN LOH, ROB MITCHELL, ROBIN POSKUS, DON SCHREMP, DANA STOFFERS, AND
>> GEORGE TSAI
>>    SOFTWARE L. COSART G. JACOBSEN S. LOH R. POSKUS D. STOFFERS
>>    HARDWARE K. BITTNER E. INGMAN D. SCHREMP
>>    MECHANICAL G. TSAI
>>    PROJECT MGR R. MITCHELL
>>    BASEHIT -- 53132
>>
>> 3) There's a pForth interpreter in this instrument too. Note
>> pr_eeprom_debug and wr_eeprom.
>>
>> That's enough hints to keep someone on the list (Magnus?) busy over
>> Christmas. Of course, if anyone knows the "confidential procedure", they
>> should just let us know...
>>
>> Thanks,
>> /tvb
>>
>> ----- Original Message -----
>> From: "Mod Mix" <modmix at t-online.de>
>> To: <time-nuts at febo.com>
>> Sent: Tuesday, December 23, 2014 3:04 PM
>> Subject: [time-nuts] HP 53131A - reset security code
>>
>>
>>  Hi,
>>>
>>> I got a used HP 53131A to which I added a stability option board (ocxo).
>>> In order to calibrate the device, a security code is needed - I don't
>>> know it. The seller doesn't know it. It's not the facorty set code.
>>> Advice on how the reset the non-volatile memory would be much
>>> appreciated.
>>>
>>> Thank you very much & happy Christmas
>>>
>>> Ulli
>>>
>>>  From the 53131A service guide:
>>> A calibration security code feature allows you to enter a security code
>>> (electronic key) to prevent accidental or unauthorized calibrations of
>>> the Counter. The security code is set to 53131 or 53132 (corresponding
>>> to the model) when the Counter is shipped from the factory.
>>> If you forget your security code, you can reset the security code to the
>>> model-number default by resetting all of the non-volatile memory to a
>>> default state (Contact Agilent Technologies for this confidential
>>> procedure).
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
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