Re: Signature Analysis without a CAT box

On Wed, 02 Jul 2003 09:58:12 -0700, John Robertson <jrr@flippers.com> wrote:

>A NOP is a NOP. Simply hardwire a 24 pin header to the required
>configuration and install it in the boot ROM socket.
>
>It seems for a Z80 that all you have to do is remove the boot ROM and as
>long as the DATA lines are all pulled high then it will happily NOP...

Actually the lines would need to be pulled low. The Z-80 used all 0's for a
NOP, which was pretty cool when patching EPROMs, since you could always write a
00 to any location in an EPROM without having to erase it first.

-Zonn
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Received on Thu Jul 3 03:28:10 2003