Thanks J. Guy

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8051 + 29c256




How you write data to the chip ?
my data : 0 ~ 63
by 8051 and WE pin of the 29c256

How you write keil code to the chip ?
first step : Compiled Hex code
by Rom emulator
second step :
Read that code in 29c256 and Rewrite to another address of 29c256
by 8051 and RD, WE pin of 29c256
(like copy)

(I used two kinds of the Writer,
But the same result.
So I think Rom emulator is no problem )

How you read data from the chip ?
1. By 8051 and OE pin of the 29c256

2. Rom emulator

What is "strange" about the data ?

if I written my data to 29c256 and read that data from 29c256 is good,
this meaning is same value.


But for My code written by Rom emulator is not good.
Rewritten data is different from original Hex Code data.

So I tested one more case.
My data written in 29c256 copy to another address and read that Rewritten data.
in this case two data is same.