Re: Request a discrete refresh circuit schematic

["Michael J. Mahon" <mjmahon@aol.com>]

Grant Stockly wrote:
> This document is very good
>
> http://www.cpm.z80.de/download/dram.pdf#search=%22interfacing%20DRAM%20to%20Z80%22

That's a very nice paper--thanks for the URL!

> Ed Eastman wrote:
>
> > Since there is no A2 hardware forum, I'll post it here...  (Sorry about
> > posting to the emulators group.)
> >
> > I need a circuit to refresh some stand alone ram for a RAM expansion
> > circuit I am designing.  (12M Ram on the IIgs)  I understand the basic
> > theory but I need an actual circuit with real RAM chips to help me
> > visualize the process. I've looked on the internet but the refresh
> > circuit is always glossed over and people are using a memory manger or
> > some such chip that I don't have access to.
> >
> > Would someone please send me a discrete schematic of a refresh circuit
> > on say, a 4 meg bank of RAM?  Or I'd be just as happy with a point to
> > some resources readily available via internet or book reference.
> >
> > I forgot to mention I'd like to use some old 8bit SIMMs I have laying
> > around.  Of course the circuit would be just as easy on a 72 pin simm.

-michael

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