INSIDE THE "OLD" NES!


On this page I will tell you about what's inside the NES
(old design). If you have anything to contribute with, then
please send an E-Mail to me. You're also welcome to send
pictures and specs about the NES (new design),
because I don't really know much about it

Note: this is made from an European Nintendo, so some of the words might
not be the same as from an American or Japanese Nintendo system.



As in all other computers, is the Nintendo controlled by by software.
The software is cartridge which you put into your NES just like a
Computer disk. When you put your cartridge into your NES, the end
of the cartridge which has an opening i put into a slot. The console
and the cartridge now has "contact". The informations can now go from
the cartridgechip to the Central Processing Unit (CPU) or the Picture
Processing Unit (PPU) in the console.

If there is dust between the console and the cartridge, the game might
not work, so remember: KEEP YOUR CARTRIDGES CLEAN!!!

Did you know, that your NES is like a Tv-transmitter? It transmit waves
which you TV can receive. The PPU is sending a compositive videosignal,
but many TV's cannot receive this signal, so it has to be converted to
a RF-signal in the RF-modulator. The RF-signal which the RF-modulator
makes, is changed to a compositive signal when it's inside the TV. This
means, that you might loose some picture quality, but if you have a TV
whith SCART/EUROPEAN - connection, you can buy a cable which does
that you can use compositive signals.

The console also gets informations from the joypad. When the CPU needs
informations from the joypad, it sends a message to the a memory in the
joypad. The memory tells the CPU when the buttons are pressed. This
might sound like it takes quite awhile before the CPU knows what to do,
but it happends in less than half a second.


PPU?

The PPU (Picture Prosessing Unit) is just like the CPU placed on the
motherboard. The PPU gets digital informations ( 0' and 1') from the
CPU and the cartridges and converts then to composive signals which
controlls every pixel and colour on the screen. 50 times per second,
the PPU gets this information and draws the screen again. Because it
goes this fast, it's like the figures moves.

CPU?

The CPU (Central Prosessing Unit) is a kind of a little telephonecentral
with a huge capacity. It makes thusinds of "phonecalls" in and out all
the time. Every 50th second when a new screen is drawn, the CPU checks
if there are any interupts. These commands comes from the cartridge which
tells the CPU to ask the Joypad about a possition, or that the CPU has to
send a sound signal to the TV's speaker. Emagine, that the cratridge is a
cookbook and the CPU is the cook, who follows the instructions in the book
there is just one difference... the CPU make it all at the same time.


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