Help with unisystem mod.

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jeroen
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Posts: 1573
Joined: Mon Oct 10, 2005 7:42 am
Location: The Netherlands

Help with unisystem mod.

Post by jeroen »

I'm modding a nes to run unisystem mario. (Haven't started yet though.)
I pretty much understand everything exept one thing. http://www.raphnet.net/electronique/nes ... ction_id=9
It's about the buffer part:
Use a buffer which will be in tri-state when CPU pin #35 is not low and connect outputs to CPU pins D5, D6 and D7. I used a 74ls125 but a 74ls244, 74ls240 or 74hc368 from another NES would work too.
Do I connect the dipswitch to input A and cpu pin #35 to C?
datasheet 74ls125:
http://www.tranzistoare.ro/datasheets/70/232291_DS.pdf

edit: also if someone could donate one of these ic's it would be apreciated.
arfink
Posts: 500
Joined: Wed Oct 19, 2005 8:12 pm
Location: Minnesota

Post by arfink »

Ahem, those IC's are cheap. Look at Jameco. Cheap. Buy them. Also, I have done things like this before, and it's not as easy as that guy makes it look. I would recommend that you learn some basic low-level electronics design before you attempt this or any other low-level mods like this. Of course, you could learn these things the hard way too if you want to.
Emulation isn't accurate. There is no substitute for real hardware!
jeroen
Senior Member
Posts: 1573
Joined: Mon Oct 10, 2005 7:42 am
Location: The Netherlands

Post by jeroen »

I'm actually pretty confident I can do this. I have the knowledge. I only asked this to make sure.
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