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Nes cartridge reproduction
http://forums.nesdev.com/viewtopic.php?f=28&t=16204
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Author:  eggman [ Thu Jul 13, 2017 12:26 am ]
Post subject:  Nes cartridge reproduction

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!

Author:  rainwarrior [ Thu Jul 13, 2017 8:29 am ]
Post subject:  Re: Nes cartridge reproduction

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?

Author:  lidnariq [ Thu Jul 13, 2017 10:43 am ]
Post subject:  Re: Nes cartridge reproduction

eggman wrote:
LED on NES is on and not blinking, but is only dim.
You are shorting +5V to ground.

Author:  eggman [ Thu Jul 13, 2017 12:07 pm ]
Post subject:  Re: Nes cartridge reproduction

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!

Author:  FrankenGraphics [ Thu Jul 13, 2017 12:13 pm ]
Post subject:  Re: Nes cartridge reproduction

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.

Author:  mikejmoffitt [ Thu Jul 13, 2017 12:18 pm ]
Post subject:  Re: Nes cartridge reproduction

If you are using Windows, you may also do this

Code:
copy /b galaxian.prg+galaxian.prg+galaxian.prg+galaxian.prg galaxian32.prg

Author:  FrankenGraphics [ Thu Jul 13, 2017 12:23 pm ]
Post subject:  Re: Nes cartridge reproduction

^^ That's even faster.

I've just started using linux (console). Could i achieve the same with mv or cp?

Author:  lidnariq [ Thu Jul 13, 2017 12:31 pm ]
Post subject:  Re: Nes cartridge reproduction

*n*x: use cat and redirects (cat file file file file > output)

Author:  eggman [ Sun Jul 30, 2017 12:33 pm ]
Post subject:  Re: Nes cartridge reproduction

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 554 times ]

Author:  Memblers [ Sun Jul 30, 2017 3:19 pm ]
Post subject:  Re: Nes cartridge reproduction

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).

Author:  eggman [ Mon Jul 31, 2017 12:40 pm ]
Post subject:  Re: Nes cartridge reproduction

That was it!! Many thanks! Very friendly community.

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

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