[Coco] Eproms

Luis Antoniosi (CoCoDemus) retrocanada76 at gmail.com
Fri Feb 15 15:39:15 EST 2013


harder than the ROM itself is a eprom programmer for that :P

On Fri, Feb 15, 2013 at 3:27 PM, Arthur Flexser <flexser at fiu.edu> wrote:

> The most prized EPROM for the CoCo would probably be the 68766, an 8K,
> 24-pin chip that was compatible with all the ROM sockets of the original
> CoCo and Tandy disk controllers (except the FD502).  Very hard to obtain
> nowadays, I believe.  (A slower version, the 68764, also exists and
> probably works okay in the CoCo.)
>
> Art
>
> On Fri, Feb 15, 2013 at 1:52 PM, Mathew Boytim <maboytim at yahoo.com> wrote:
>
> > Hi John,
> >
> > Thanks for the reply but I think your numbering is off - a 27C64 would be
> > 64 kbit in an 8kx8 configuration.  27C32 would be 32 kbit in 4kx8.
> >
> > The transition from 24 pins to 28 pins usually occurs between 2732 and
> > 2764 (4k and 8k).  The Model 1 w/ Level 2 Basic has 12k bytes of ROM.  At
> > least the early one that I had had two ROM's - one 8k, one 4k, both were
> in
> > 24 pin packages - and both on a satellite board that was connected to the
> > mainboard by a ribbon cable an a few wires.  I think there was like a
> 2564
> > that was kinda rare but it was an 8k in a 24 pin package.  I think it was
> > more convenient to replace the 8k ROM with a 2564 if you could find one.
>  I
> > think eventually I replaced both ROM's and the satellite board with a
> > single 16k EPROM and a few skywires.
> >
> > I didn't know if there was a particular EPROM that worked out best in the
> > Coco.  I'm more of a model 1/3 enthusiast but a friend clued me into the
> > Coco mailing list and I've been monitoring some of the discussions.
> >
> > Thanks again,
> >
> > Matt
> >
> > --- On Fri, 2/15/13, John Donaldson <johnadonaldson at sbcglobal.net>
> wrote:
> >
> >
> > From: John Donaldson <johnadonaldson at sbcglobal.net>
> > Subject: Re: [Coco] Eproms
> > To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> > Date: Friday, February 15, 2013, 11:15 AM
> >
> >
> > If you talking 8K EPROMS then  something along the line of a 27C010 which
> > is a
> > 8KX8 (64K) EPROM. These are the same size as the Basic ROMS.
> > IIRC   a 27C512 EPROM is a 4KX8 (32K) EPROM which may be the smallest you
> > want
> > to go with.
> >
> > JohnD.
> >
> >
> >
> >
> > ________________________________
> > From: Mathew Boytim <maboytim at yahoo.com>
> > To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> > Sent: Fri, February 15, 2013 10:19:17 AM
> > Subject: Re: [Coco] Eproms
> >
> > Which EPROMs are desirable for the coco?  I used to have stacks of EPROMs
> > but
> > when younger my daughter would make stuff with them and the antistatic
> > foam and
> > they got bent and damaged but I didn't care - and eventually pitched
> > them.  I
> > still have a small assortment though.
> >
> > Matt
> >
> > --- On Fri, 2/15/13, John Donaldson <johnadonaldson at sbcglobal.net>
> wrote:
> >
> >
> > From: John Donaldson <johnadonaldson at sbcglobal.net>
> > Subject: Re: [Coco] Eproms
> > To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> > Date: Friday, February 15, 2013, 8:02 AM
> >
> >
> > Sorry Luis, but I am all out of EPROMS.
> >
> > JohnD
> >
> >
> >
> >
> > ________________________________
> > From: Luis Fernández <luis46coco at hotmail.com>
> > To: COCO <coco at maltedmedia.com>
> > Sent: Thu, February 14, 2013 10:22:38 PM
> > Subject: Re: [Coco] Eproms
> >
> > Hi John Donaldson
> >
> > Still have eprom?
> > I would like to change my controller to 28 pin and still use your eprom
> >
> >
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-- 
Long live the CoCo



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