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eprom and cartridge pinouts

Posted: Sun Oct 09, 2016 2:31 pm
by dvoika
Hello my friends :) i want try make famicom card but diagram/pinouts does not fit on pictures

27C256
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Image

Q7 is D7 ? and next and next... I'm confused pls help
whats EXP, E, G, where is chr /wr :D

Re: eprom and cartridge pinouts

Posted: Sun Oct 09, 2016 5:13 pm
by Memblers
Yes, Q7 is D7. The EXP pins are audio in/out. /G is output enable, /E is chip enable. CHR /WR is only used with CHR-RAM, can't do anything with that if you're using ROM.

On the CHR side, CHR /RD would be connected to output enable, and usually CHR /A13 would be connected to chip enable.

Re: eprom and cartridge pinouts

Posted: Mon Oct 10, 2016 12:13 am
by dvoika
Here I have tried to break down, But I have a doubt is
???1,2,3,4,5,6,7 heelp please :mrgreen:
Image

???1 on (OE)
???3 is joint 44/32 pins and PRG A15 right? :( im comfused

Re: eprom and cartridge pinouts

Posted: Mon Oct 10, 2016 12:40 am
by Memblers
That pin 44 is what I call PRG /CE, it will be active (low) whenever the NES is accessing memory at $8000-$FFFF. So you'll probably want that connected to the /CE pin of your PRG-ROM.

Read the signal descriptions here, that should help clear things up.
http://wiki.nesdev.com/w/index.php/Cartridge_connector

Re: eprom and cartridge pinouts

Posted: Mon Oct 10, 2016 1:07 am
by dvoika
tnx !! and sorry my english