Re: Transwarp IIe revisited

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

mdj wrote:
> On Dec 8, 11:50 pm, Linards Ticmanis <ticma...@gmx.de> wrote:
>
> > David Wilson wrote:
> >
> > > On Dec 8, 7:51 pm, mdj <mdj....@gmail.com> wrote:
> > >
> > > > FWIW, my card has 80ns RAM on it. I imagine someone has swapped the
> > > > RAM at some earlier point, 150 is way to slow
> >
> > > I just took a look at mine and it has 8x HM50256-15 NMOS DRAM chips
> > > (week 50 of 1985).
> >
> > Hmmm... I have HM50256P-15 from WK13/86. Then speed is maybe not the
> > issue after all.
>
>
> Unless one or more of them is faulty...
>
> I didn't do the math, but I would have thought 150ns was marginal at
> 3.6Mhz considering the Apple II refresh scheme.

The Apple II "interleaved access" scheme will not apply to
DRAM on the Transwarp card.  It will have its own, more conventional
refresh method.

-michael

NadaPong: Network game demo for Apple II computers!
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