Date   : Tue, 10 Aug 2004 14:40:09 +0200
From   : John Kortink <kortink@...>
Subject: Re: ROM Burning

On Tue, 10 Aug 2004 13:12:57 +0100, "Chris Priest"
<chris.priest@...> wrote:

>I have a selection of 27C256 roms OTP version, I thought I would be able
 to
>use these, but although it burns OK, the rom is not recognised.

You can use an xxx256 but the top address pin is usually
tied to 5V on the motherboard, so the ROM image appears
at offset 0x4000 in the PROM, not 0, where you probably
put it.

Best is to copy the image to 16K intervals, i.e. in this
case put it in twice, at offset 0 and at offset 0x4000
(16K). You should still be able to do this (everything
from 0x2000 onwards will still be FF, hence programmable).


John Kortink

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