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PostPosted: Tue Jan 19, 2016 7:45 pm 
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So some of you may have heard of Pseudo Saturn which flashed over your original Action Replay or Gameshark code to boot backups. Only Issue is codes and save backup will no longer be accessible.

To get around this figured I'd replace the original 2x AT29C010A(128K) with 2 W27C020(256k) and swap A17 high and low to swap menus. It works but the save back function on the PAR side doesn't work and actually causes the Saturn to crash and reboot half the time. Other times it will go through with the copy but when you go back to the menu it's not there.

These two chips are pin for pin the same except for A17 being there on the 27C020 and pin 1 is VPP, both are NC on the original chips. I thought just tying VPP to 5v should be the way to go but that doesn't help. Also tried jumping the PGM pin over to it but get the same results? Any suggestions why it wont write saves to the cart?

Edit: I read and compared the data sheets for the two chips and think the reason it's not working is because the Atmel 29C010A supports programming by a sector basis while the Winbond W27C020 has to be fully erased and then fully reprogrammed, no single sector programming. Is that about right?


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PostPosted: Tue Jan 19, 2016 11:02 pm 
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darknezz19 wrote:
Edit: I read and compared the data sheets for the two chips and think the reason it's not working is because the Atmel 29C010A supports programming by a sector basis while the Winbond W27C020 has to be fully erased and then fully reprogrammed, no single sector programming. Is that about right?


Yeah. On a lot of flash chips, the programming/erase procedure is the same, but the erase sector sizes are different. I looked at the AT29C020 and it has a different sector size from the AT29C010, so even that probably wouldn't work right either.


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PostPosted: Tue Sep 05, 2017 1:43 pm 
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That latest version of pseudo Saturn Kai iso flasher supports these chips now. Was able to flash 2 banks with the highest address line tied top vcc and vss.

Pretty simple but if anyway wants to try.

https://www.reddit.com/r/SegaSaturn/com ... aves_in_1/


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