Nes cartridge reproduction

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Nes cartridge reproduction
by on (#200106)
Hi. I've tried my first cartridge reproduction. I used Super Mario 1 as donor cartridge and copied Galaxian on the Eproms. I tested all connections. However, the screen remains blank. LED on NES is on and not blinking, but is only dim. Does anyone know why this doesn't work? Thanks!
Re: Nes cartridge reproduction
by on (#200122)
Super Mario Bros has 32k PRG, and Galaxian has 8k. How did you fill up the other 24k of space? Did you duplicate Galaxian's ROM 4 times to fill it up (correct), or did you just leave a bunch of empty 0s (incorrect) or something?
Re: Nes cartridge reproduction
by on (#200131)
eggman wrote:
LED on NES is on and not blinking, but is only dim.
You are shorting +5V to ground.
Re: Nes cartridge reproduction
by on (#200137)
Thanks, rainwarrior. You are right, I did not fill up the rest. For a beginner, how do I do that?

@ lidnariq: I will check that. Thanks!
Re: Nes cartridge reproduction
by on (#200138)
If you have the binary, you can write in a .txt file

.incbin "galaxian.bin"
.incbin "galaxian.bin"
.incbin "galaxian.bin"
.incbin "galaxian.bin"

provide a path between the "" if necessary, and assemble in any assembler. sometimes the directive is called .bin instead of .incbin. Both may work in some assemblers.

That will pack four copies of galaxian in one binary to fill up ROM space.

You can also roll the four includes in a .repeat / .rept directive, bit if you have to look that up, it's just faster to type .incbin four times and go.
Re: Nes cartridge reproduction
by on (#200139)
If you are using Windows, you may also do this

Code:
copy /b galaxian.prg+galaxian.prg+galaxian.prg+galaxian.prg galaxian32.prg
Re: Nes cartridge reproduction
by on (#200140)
^^ That's even faster.

I've just started using linux (console). Could i achieve the same with mv or cp?
Re: Nes cartridge reproduction
by on (#200142)
*n*x: use cat and redirects (cat file file file file > output)
Re: Nes cartridge reproduction
by on (#201245)
Many thanks, that helped.

Now, I used Wild Gunman. And it runs. It even reacts to the lightgun.
Except that the background graphics is missing. Please see image.
I tested all connections a thousand times. Does that mean the
chr eprom is somehow distorted? I'm reluctant to de-solder
everything...

Attachment:
IMG_7140.JPG
IMG_7140.JPG [ 3.26 MiB | Viewed 4002 times ]
Re: Nes cartridge reproduction
by on (#201267)
It's probably the mirroring. There is a jumper on the board where you can select H or V. Try setting it so H is closed and V is open (or whatever is the opposite of what it is now).
Re: Nes cartridge reproduction
by on (#201322)
That was it!! Many thanks! Very friendly community.

All the effort for... Wild Gunman... :)