Core memory emulator using non volatile ram.

[Guy Sotomayor Jr]

> On Dec 15, 2018, at 7:09 PM, allison via cctech <cctech at classiccmp.org> wrote:
> 
> On 12/15/2018 01:01 PM, Guy Sotomayor Jr via cctech wrote:
>> FRAM or MRAM.  I make extensive use of them in my projects.
>> 
>> Everspin has a few (all SMT and 3.3v).  As I recall they run ~$20/ea for 4Mb (512K x 8 or 256K x 16).
>> 
>> TTFN - Guy
>> 
>>> On Dec 15, 2018, at 1:22 AM, Rod G8DGR via cctalk <cctalk at classiccmp.org> wrote:
>>> 
>>> I have an idea to produce an MM-8  clone using RAM that acts like core when turned off.
>>> Can anybody suggest a chip that will do this?
>>> 
>>> Rod Smallwood
>>> 
>>> 
>   Flash, EEprom and Magnetic FRAM and MRAM) types
> have many unacceptable
> properties for a random access read write memory. 

I think you’re mistaken about FRAM and MRAM.  They are byte oriented devices
and are designed to replace SRAM + battery.  Which in my mind makes them
preferable as they reduce parts count.  The current MRAM has unlimited write
endurance (same as SRAM) and depending upon the part is 35-55ns access/cycle
time.  FRAM has a similar access time but requires an internal restore so it’s cycle
time is about 2x (one of the reasons I prefer MRAM now).

TTFN - Guy