[time-nuts] HP3458A calibration memory backup

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Aug 11 17:06:07 EDT 2014


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In message <BLU170-W839A5D44106A8AED622D67CEED0 at phx.gbl>, Mark Sims writes:
>I did some more playing around with the 3458A memory dumper this
>weekend.   I built up another system using a different
>computer/cables/software/GPIB interface (one I built using an AVR
>chip that emulates the Prologix RS-232/USB converter).   I noticed
>than  a couple of dumps of the CAL ram (out of maybe two dozen
>runs) had one byte near the end of the RAM (in that same string of
>01 bytes) sometimes read as 00 or 05.  This was with a different
>3458A and it has been continuously powered for a couple of days.
>Perhaps the memory chip is not enabled at those addresses and it
>is reading a floating bus? 		 	   		  

Hm, that's interesting, I havn't seen that myself, but somebody
else reported something similar some days ago...


-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.



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