Re: Why can't 27C64 replace a 2764?

["Glenn Jones" <apple2stuff@rogers.com>]

"Robert J. Stevens" <atreborz@execpc.com> wrote in message
41A7873A.F8DA4DA1@execpc.com">news:41A7873A.F8DA4DA1@execpc.com...
> "Robert J. Stevens" wrote:
>
> > Glenn Jones wrote:
> >
> > > I am trying to read a 27C64 EPROM chip with my old apple 2 eprom
programmer.
> > > It supports and reads 2764's fine but won't seem to read a 27C64. The
pinouts
> > > are the same and both require 5v to read ...
> > > Any thoughts?
> > > Glenn
> >
> > I am trying to read both 2764's and a 2716. I built a breadboard Reader
and was
> > able to read out a AM27S19DC 32x8 Prom.
> > But using the same technique I can't get the 2716 to read it seems to be
all FF's.
> >
> > Only got one so can't check with another chip.
> > I am going to stretch the wires to use a 2764 which I have a bunch.
> > [Old ones given to me by a friend so they might be programmed]
> > I see a 27c512 in the box and some 27128's
> > I have a Pro-Log M980 with a Personality Module 9080.
> > It accepts both 24 pin and 28 Pin Proms but I'm not sure what Chips it
will read
> > and program.
> > If I can read a 2764 on my B/B then I may try to see if I can get the
PRo to read
> > them.
> > If I measure the Pinouts I may be able to determine what Pins are
Addresses and
> > what pins are Data

Robert, have you looked for datasheets?

http://alldatasheet.com/view.jsp

enter M27 in the search criteria field.


> > I am receiving and Old Apple ][ Prom Burner so that may help
> > Any Thoughts
> > Bob in Wisconsin
>
> I was able to read some of my 128 and 512 EPROMS. some came up all FF's
and the
> others show low's .50 approx volts on all data lines.
> Got a Eraser Coming so will see if erasing restores to all FF's
> Gotta try the Pro-Log next
>