Re: BlueFlash Progress Update

[vinchysky@yahoo.com]

On 6 24 ,   7 55 , "Michael J. Mahon" <mjma...@aol.com> wrote:
> vinchy...@yahoo.com wrote:
> >>If some CF cards work and others don't, it is almost certainly
> >>a symptom of failing to meet the timing specs for the CF standard.
>
> >>I urge you to check setup and hold times at the CF card interface
> >>to verify that the specs are being met.
>
> >>When they are met, virtually all CF cards will work fine.
>
> >>BTW, an Apple II is incapable of using the "high speed" cards
> >>to advantage, so that slower, cheaper cards would be preferred.
>
> > Indeed, I also thought it was the timing problem. However, I have not
> > much I can do to make the timing better since I use ARM on-chip
> > external memory controller to generate signals for accessing CF card,
> > USB host controller and on-board SRAM. They all work except some CF
> > card can't. ARM doesn't allow too flexible signals to be generated and
> > I don't have any glue logic or spare logic on CPLD to generate better
> > timing. Since Sandisk is THE leading memory card provider, so I think
> > it is fine to restrict the use of Sandisk card. CF card isn't really
> > expensive, a 512M Sandisk Ultra ][ card cost US$15 shipping included.
> > And you don't really need too many CF card since 512M allows you to
> > store around 3600 .DSK images, so you probably only need one CF card.
>
> Interesting, since ARM chips of presumeably similar design are used
> in many cameras, which are relatively tolerant of various manufacturer's
> CF cards.
>
> > BTW, in BlueFlash, Apple ][ doesn't see CF card, CF card is accessed
> > directly by ARM and ARM runs at 57MHz, so a fast card does help a lot
> > in accessing CF card. In my test, to load a .DSK image from CF card to
> > the on-board SRAM happens almost instantly!
>
> I see.  But even a slow card could transfer a 140K disk image before
> you could get your finger off the key.  ;-)
>
> -michael
>
> NadaNet file server for Apple II computers!
> Home page:  http://members.aol.com/MJMahon/
>
> "The wastebasket is our most important design
> tool--and it's seriously underused."-         -
>
> -         -

Hi Michael,

I can try other ways to make virtually all CF cards to work, but I am
extremely exhausted (I still got a full time job), so I will just let
it is.