[rescue] NVRAM for Blade 100/150
peter at ashlyn.co.uk
Sun Feb 28 08:51:19 CST 2021
I now have the PCBs in house for the adapters and have tested it as working
well with the Dallas part.
Here are a couple of photos FYI.
I have a solution for the 100/150 (may need these for the V100/120 as well, I
forget what works with them). I tried a few models of NVRAM without success,
but I noticed that Maxim/Dallas produce a larger memory version of the DS1553
called a DS1554. The downside is that it is 32 pins, similar pin out and the
same functionality. I tied the extra address pins high and made up a hack to
prove it works.
I have a few orders for them, so am going to use a prototype through plated
board, 32 pin socket and 28 header pins to satisfy them. I am however
ultimately aiming to have some adapter PCBs made which appear to be pretty
cheap if ordered online, so if anyone is interested in any let me know.
Anyone have a suggestion for which NVRAM, that is actually available to buy,
works in the Blade 100?
The original M48T59 has been NLA for a long time now and the DS1553 I have
been using is also now NLA. For the OBP3.X systems you can use an alternative
M48T part, but I have not found one to use in the OBP 4.X systems such as the
As anyone who has played with these parts, using the wrong NVRAM gives an
error on boot of
"(Can't load tod module) Program terminated"
More information about the rescue