Re: More fun with Freed Z80

[Steven Hirsch <snhirsch@gmail.com>]

a2retro wrote:
>  To: a2retro
> a2retro wrote:
> > alex.freed.007 wrote:
> >
> > > The 128K version is particularly easy to use with a battery back-up as
> > > it has an active high second chip select. Most likely just adding a 
> >  > diode and a coin cell will make it NV.
> >
> > I have seen this implemented on a few other projects. zxmmc+ for example.
> >
> > I plan to use this approach for my //cmxp project.
> >
> > Cypress also has an interesting part CY14B104L-ZS45XC - combo 
> > SRAM/Flash with autosave.
> >
> > Glenn
>
> For anyone updating their card to a 512K ram - double check the 
> datasheet from your vendor of choice, as I see there doesn't seem to be 
> a standard on pin A17 and A18. They are interchanged across vendors.

Hmm.  All the static memory I've seen (628512LP-70 and AS6C4008-55) have A17 
on pin 30 and A18 on pin 1.  Are you saying that the SRAM/Flash differs?