89s52 platform

I wish to implement 512Kb memory interface as described in the assembler document please help
Atmel 89S52

I just cannot find the Atmel AT89S52. I have reinstalled the software a number of times. The device database doesn't show ATMEL devices at all.
89s52 problem

I have a program that is working fine with 89c52, but when I program 89S52 it is not working. I am using Superpro programmer for programming.
Atmel 89S52

I just cannot find the Atmel AT89S52. I have reinstalled the software a number of times. The device database doesn't show ATMEL devices at all.
89s52 platform

I wish to implement 512Kb memory interface as described in the assembler document please help