Can I use a 27C4001 eprom instead of a 27C020?

[Nick]

I can't get me hands on a 27C020 for a few weeks, but I do have some 27C4001
EPROM's that have been uv erased. I have an EPROM burner (willem universal),
however, I not sure if I can use the 27C4001 as it is 512k as opposed to
256k. I guess if I duplicate the data over the two halves of the chip, then
it should be okay?

 

[Mochuelo]

On Tue, 05 Apr 2005 07:51:31 GMT, "Nick" <nickz@bigpond.net.au> wrote:

I can't get me hands on a 27C020 for a few weeks, but I do have some 27C4001
EPROM's that have been uv erased. I have an EPROM burner (willem universal),
however, I not sure if I can use the 27C4001 as it is 512k as opposed to
256k. I guess if I duplicate the data over the two halves of the chip, then
it should be okay?

That would work, but it is not needed. The 27C4001 has one more
address line. In your application circuit, if you keep that extra
address line tied to gnd, you only need the first half of it to be
meaningful. The first half is the range of addresses you span by
keeping the most significant address bit equal to 0, during
programming.

Best.