NES PPU dissection

[ttlworks]

The NES (Nintendo Entertainment System) is a 6502 related video game console.
It was produced my Nintendo from 1985..1995.

The PPU (Picture Processing Unit) inside the NES generates the picture.
It's a custom chip, developed by Rico.

This dissection is about three different variants of the PPU:
RP2C02 generates a NTSC composite video signal,
RP2C07 generates a PAL composite video signal,
RP2C04 generates an analog RGB video signal.

[ttlworks]

For >25 years old 'video game console' chips which are out of production,
dissecting microscopic silicon pictures which are done by hobbyists
and which are openly floating around in the internet is supposed to be legal.

My schematics from chip dissections always are free as in 'free beer'.
If intermediate steps of a dissection end up in a book "by accident",
this also is supposed to be legal.


But for legal/political reasons,
this time the dissection has to come without the usual text,
and without the usual silicon pictures of the chip.

BTW: the orientation picture is a scaled down image of a chip picture
which is (c) by Visual6502.org.
Thanks to BigEd and the Visual6502.org team for their efforts
for preventing technical knowledge about old/obsolete technology from sinking into /dev/null.

[ttlworks]

NES PPU schematics, rev1.

PPU_dissect_v1.zip

(11.56 MiB) Downloaded 911 times

difference to rev0:
Fixed some bugs in the PAL phase decoder and the RGB circuitry.
Made some of the signal names more consistent to breaknes.
Cleaned up the schematics a bit here and there.

;---

That's all for now.
Frank currently is "missing in action", so the 6522 dissection has not started yet.

[Greg816v2]

Very cool, thanks for sharing!

[ttlworks]

Thanks for the appreciation.

I'm trying to dig into the NES APU (RP2A03) until Frank surfaces again.

[fhw72]

ttlworks wrote:

Thanks for the appreciation.

I'm trying to dig into the NES APU (RP2A03) until Frank surfaces again.

I'm back... somewhat.

[ttlworks]

Frank: welcome back, and nice job with polygonizing the 6522.

So I'm now starting with the 6522 dissection.
APU\RP2A03 will have to fill the gap whenever I have free capacity.

//Frank has higher priority because he was first.

[fhw72]

ttlworks wrote:

Frank: welcome back, and nice job with polygonizing the 6522.

So I'm now starting with the 6522 dissection.
APU\RP2A03 will have to fill the gap whenever I have free capacity.

//Frank has higher priority because he was first.

Here's a small preview for the interested ppl here:

[org]

Finally, this monumental work is published! Congratulations!

Minor errors will be corrected in time. Those who have been engaged in circuitry for a long time know that "digital logic is very logical", so the circuits will settle down properly sooner or later.

Enjoy your trip with 6522

[ttlworks]

Thanks, org.

To me, RP2A03 somehow looks like "6502 core + DMA controller + sound" on a single chip.

Already had the dissections: 6502 core, 8726 DMA controller, 6581 SID sound chip.

So I think I know what to look for when returning to the RP2A03 later...

[ttlworks]

Edit:
MOS 6522 dissection is here.

The situation here is, that too many >young enthusiastic academics< are scurrying around me,
in desperate seek for somebody to burden with some extra work //which probably doesn't get paid.
It would be helpful for the chip dissections if they would be spending less time with me...

[BigEd]

Very interesting - is that a different chip layout than the one here? The CA2 pad seems to be in a different place...
http://ic.onidev.fr/map/6522.html

[ttlworks]

Ed, the chip layout in your link has "R6522" on the silicon, so I assume it's a Rockwell part.
To me, that layout looks different from the MOS 6522 chip layout.

BTW: Frank told me, that all of the MOS 6522 chips are "revision 0".

[BigEd]

Ah, Rockwell, oops!

[fhw72]

ttlworks wrote:

Ed, the chip layout in your link has "R6522" on the silicon, so I assume it's a Rockwell part.
To me, that layout looks different from the MOS 6522 chip layout.

BTW: Frank told me, that all of the MOS 6522 chips are "revision 0".

Yes... all MOS/CSG6522 produced until EOL (of CSG and 6522... LOL) were revision 0.
Please check the marking "10" (if present which means: 1 -> NMOS, 0 -> Rev.0)