[Coco] EEPROM

[Bruce Borer]

Be aware the CoCo does not chip select the ROMs for writing.
I have made an adaptor to allow writing 4M Flash chips and to select
which page is active.
My CoCo3 is acting up so I have not fully tested my board.
If anyone is east of Toronto that could help me test I would appreciate it.
Bruce

On Fri, Jun 28, 2024 at 10:55 PM dave--- via Coco <coco at maltedmedia.com> wrote:
>
> Thanks, Dave. I was unaware of those chips. After looking at their data sheets it seems they may have continued to use the “27” designation because of their strong similarities to a standard EPROM. It appears that both of them are programmed like an EPROM and that they can be erased only as a whole chip which is also similar to an EPROM but done electrically instead of with UV.
>
>
> -Dave Philipsen
>
> > On Jun 24, 2024, at 10:24 AM, David Ladd via Coco <coco at maltedmedia.com> wrote:
> >
> > On Sun, Jun 23, 2024 at 10:13 PM Dave Philipsen via Coco <
> > coco at maltedmedia.com> wrote:
> >
> >> Dave,
> >>
> >> I think he is specifically looking for EEPROM. the 27 series is EPROM
> >> and the 29 series is flash.
> >>
> >
> > David,
> > In this case if you look up the specifications of the SST27SF256 it is
> > listed as a FLASH according to the datasheet.  I have used these in my
> > CoCo3 without problems.  Also I have also used the W27C512 which is listed
> > as an EEPROM.  So either cheap should work fine.
> >
> > I tried to provide the PDF, but my last attempt of this message with the
> > PDF was rejected by a moderator.  So you will have to look up the PDF for
> > the SST27SF256 yourself.
> >
> >
> >>
> >>
> >>> On 6/20/2024 1:08 PM, David Ladd via Coco wrote:
> >>> <cut>
> >>
> >
> > --
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>
>
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