[time-nuts] RS 232 to GPIB update on IOtech 488 series

Mike S mikes at flatsurface.com
Thu Nov 17 22:36:47 EST 2011

At 05:13 PM 11/17/2011, paul swed wrote...
>The eprom and the addition to the ram socket of a DS1216 clock and 
>battery chip...Further I had NV corruption failing the 488ex. It 
>actually all seemed to work just fine actually. Just a red error light.
>This was fixed by;
>Pulling the sram chip and grounding all pins for 30 min.
>Command a warm reset and then a save. The light went away.

The DS1216 is really just a DS1315 chip in a (mostly) pass-through 
socket. I repaired mine by chipping away the potting compound, removing 
the imbedded batteries, and using wire wrap wire to connect to external 
CR2032 (original were CR1216) battery holders. I also replaced the 
1990's vintage SRAM (UM62256A in mine) with newer, even lower power 
ones (CY62256NLL-70PXC), which draws a typical 0.1 uA standby, vs. 50 
uA (max) on the old.

The original was good for ~ 10 years, so the combination of larger 
batteries (~10x capacity), and lower draw SRAM makes me believe mine 
may be good for 50 years or more (ST app note AN1012 is an interesting 
read), and the batteries are now easily replaceable.

>The eproms...

I have version 1.4 for the "EX". I think the "A" box is newer, but they 
dropped the RTC, based on the docs. What version(s) do you have?

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