[Coco] 28pin AT29c256 in a coco2?

[Mike Pepe]

The CoCo3 does support an 32k internal ROM, but the CoCo2 does not.
(directly anyway)

You could modify the chip-select logic (the 74LS138 circuitry) so that it
would respond to all addresses $8000-$FEFF- the mod would be fairly trivial.

> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of chris
> Sent: Monday, October 15, 2012 2:51 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] 28pin AT29c256 in a coco2?
> 
> OK james thanks.
> 
> The pinouts must be the same because I drop an old style 27c256 (286
> ROMs) uv eprom chip in the burner and it reads it fine.
> 
> Now here is a wacky idea. If im using bigger flash chips then the stock
16K
> one could I then just flash in cartridge images at the expansion port
address?
> I know it would make the real port useless but would be cool if I only
cared
> about running a single program. Or is the coco's rom socket hardwired in a
> way that thats not possible?
> 
> 
> 
> thanks.
> =chris
> 
> 
> 
> On Oct 15, 2012, at 9:27 AM, jdaggett at gate.net wrote:
> 
> > On 14 Oct 2012 at 22:43, chris wrote:
> >
> >> The Atmel AT29c256-90PI chips are all over ebay for cheap. Can I use
> >> these in a CoCo2 with out doing any hardware hacking?
> >
> > Be careful of pinouts is about the only thing that I can offer. The
> > 29C256 is a 32Kx8 Flash.
> > Once programmed the CPU sees it as a memory and is not particular as
> > to what type it is.
> > The speed grade is 90nS so it is far faster than needed on any COCO.
> >
> > IF the pinouts match what is currently on board then you should have
> > little or no problems.
> > The voltage ratings are the same so have at it.
> >
> > james
> >
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> 
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