In message <20100608164407.a9783112...@mail.ebirds.it>, Marco IK1ODO -2 writes:
>Speaking of the 3458A, it has three DS1235Y-150 non volatile SRAM on >the CPU board. Each is a 32K x 8 bit, so there is a lot of info inside. >As the useful life of those is in the order of 10 years and most >3458A a re now 10 to 20 year old, is there a possible replacement? >Possibly with a more modern component? I replaced all the NVRAM's in mine last month, no issues. There are plenty of NVRAMs to be had as new. >Also, of course it would be a good idea to read and save the contents >of the SRAMs before replacing, but... is any custom data in them that >cannot be rewritten with a complete recalibration? The CALRAM contains a number of "magic" counters, one of which is called "destructive overloads" that a calibration cannot possibly restore. But from a functional point of view: no. You can read out the memory with the undocumented "MREAD" command, but the CALRAM is protected by various tricks, so you cannot just use the MWRITE command to restore it. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
