Hi everybody! I'm Doctor Nick Rivera with another exciting installment of "Obsessed with Mapper Hardware"; an episode I like to call, "Weekend of the Dead Programmer".
Yea, don't be too harsh on me. When you do as many mapper topics as I do you try to spice up the intro
Anyway, I've finally decided to start at the beginning and actually get something accomplished. I have made an NROM development board that accepts 28x256 ROM chips, and it actually works! Here's the obligatory project page with basic instructions and grainy photos of the build process.
Once I completed the board I fought with my craptastic Willem PCB5 programmer for several hours untill I figured out that the A14 line has gone out (in addition to A15 and A18, which went out previously).
So I spent Sunday building an EEPROM programmer with an Arduino, a breadboard, some shift registers and about 60 feet of jumper wire Finally at around 10 PM last night I ran my first code on an NES. I was so proud, as was my Wife (she's a geek too ).
I'll upload pics of the programmer and first execution later.
So, for future plans I am wanting to make it so the NES can write bytes of data to the EEPROM. Next I want to make some kind of communication through the controller port happen to the Arduino (just as a USB interface to the PC) so I can rewrite the whole program from the PC. Finally I want to rig up a boot ROM so I can do all of this without having to embed support for it within the game code.
I think all of this is pretty easy to do with my current setup (except the boot ROM bit, that will take a daughter board and a lot of wires).
Does anyone know where you can buy 256-byte parallel EEPROM or Flash these days? Or is there a way to run PRG-ROM off of a serial ROM? Either one would really help out on the boot loader bit.
Yea, don't be too harsh on me. When you do as many mapper topics as I do you try to spice up the intro
Anyway, I've finally decided to start at the beginning and actually get something accomplished. I have made an NROM development board that accepts 28x256 ROM chips, and it actually works! Here's the obligatory project page with basic instructions and grainy photos of the build process.
Once I completed the board I fought with my craptastic Willem PCB5 programmer for several hours untill I figured out that the A14 line has gone out (in addition to A15 and A18, which went out previously).
So I spent Sunday building an EEPROM programmer with an Arduino, a breadboard, some shift registers and about 60 feet of jumper wire Finally at around 10 PM last night I ran my first code on an NES. I was so proud, as was my Wife (she's a geek too ).
I'll upload pics of the programmer and first execution later.
So, for future plans I am wanting to make it so the NES can write bytes of data to the EEPROM. Next I want to make some kind of communication through the controller port happen to the Arduino (just as a USB interface to the PC) so I can rewrite the whole program from the PC. Finally I want to rig up a boot ROM so I can do all of this without having to embed support for it within the game code.
I think all of this is pretty easy to do with my current setup (except the boot ROM bit, that will take a daughter board and a lot of wires).
Does anyone know where you can buy 256-byte parallel EEPROM or Flash these days? Or is there a way to run PRG-ROM off of a serial ROM? Either one would really help out on the boot loader bit.