Re: Batteryless mod.

On 26.09.2013 19:15, Kaz Kylheku wrote:
> On 22.06.2013 19:53, Kaz Kylheku wrote:
>> Hi all,
>>
>> There used to be a batteryless mod for the MP-1, but it's
>> proving hard to find.
>
> [ SNIP ]
>
>
>> Intersil (formerly Xicor) has a unit called the X28HC64 that looks
>> good. It has a 100,000 write cycle endurance, and 100 year retention.
>> Someone is selling these on eBay, I've noticed.
>
> Hello again, MP-1 slinging friends,
>
> I now have two Xicor X2864AD-25 EEPROM chips!

Unfortunately, though these chips are pin compatible with the
Toshiba TC5565AP static RAM, they have monstrously long write
cycles that the MP-1's firmware won't deal with.

The battery backed SRAM can write a byte in about the same
time as it can read it: around 100 ns.

The Xicor EEPROM can read in about that time, but the write
cycle is measured in *milli* seconds, oops! :)

(You can poll it to detect when it's finished writing using
a special protocol.)

I think this chip would be an option if we could tweak the MP-1
firmware.

:(