6502.org Forum  Projects  Code  Documents  Tools  Forum
It is currently Thu Nov 21, 2024 10:44 pm

All times are UTC




Post new topic Reply to topic  [ 18 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: NES PPU dissection
PostPosted: Thu Apr 28, 2022 7:15 am 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
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.


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu Apr 28, 2022 7:17 am 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
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.


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu Apr 28, 2022 7:18 am 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
NES PPU schematics, rev1.

Attachment:
PPU_dissect_v1.zip [11.56 MiB]
Downloaded 863 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.


Last edited by ttlworks on Mon Aug 29, 2022 8:46 am, edited 2 times in total.

Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Tue May 03, 2022 10:51 pm 
Offline

Joined: Tue Jan 11, 2022 5:56 pm
Posts: 17
Very cool, thanks for sharing!


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Wed May 04, 2022 9:41 am 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
Thanks for the appreciation.

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


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu May 05, 2022 5:57 am 
Offline

Joined: Thu Jul 20, 2017 9:58 am
Posts: 91
ttlworks wrote:
Thanks for the appreciation.

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


I'm back... somewhat. 8)


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu May 05, 2022 6:48 am 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
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.


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu May 05, 2022 8:09 am 
Offline

Joined: Thu Jul 20, 2017 9:58 am
Posts: 91
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:

Attachment:
MOS6522R0.jpg
MOS6522R0.jpg [ 985.46 KiB | Viewed 2213 times ]


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu May 05, 2022 9:18 am 
Offline
User avatar

Joined: Fri Jun 22, 2012 7:39 am
Posts: 201
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 :)

_________________
6502 addict


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu May 05, 2022 9:35 am 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
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...


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Wed Jun 29, 2022 3:29 pm 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
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...


Last edited by ttlworks on Mon Jul 11, 2022 9:10 am, edited 6 times in total.

Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Wed Jun 29, 2022 4:35 pm 
Offline
User avatar

Joined: Thu Dec 11, 2008 1:28 pm
Posts: 10985
Location: England
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


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu Jun 30, 2022 4:56 am 
Offline
User avatar

Joined: Fri Nov 09, 2012 5:54 pm
Posts: 1431
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".


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu Jun 30, 2022 7:35 am 
Offline
User avatar

Joined: Thu Dec 11, 2008 1:28 pm
Posts: 10985
Location: England
Ah, Rockwell, oops!


Top
 Profile  
Reply with quote  
 Post subject: Re: NES PPU dissection
PostPosted: Thu Jun 30, 2022 8:37 am 
Offline

Joined: Thu Jul 20, 2017 9:58 am
Posts: 91
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)


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 18 posts ]  Go to page 1, 2  Next

All times are UTC


Who is online

Users browsing this forum: pdragon and 52 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: