高级任天堂娱乐系统 (ANES) – 改装为使用双 PPU 的 NES

高级任天堂娱乐系统 (ANES) – 改装为使用双 PPU 的 NES
Advanced Nintendo Entertainment System (ANES) – NES Modded to Use 2 PPUs

本仓库提供了修改任天堂红白机（NES）以使用两个图像处理单元（PPU）的说明，旨在实现增强的图形功能，如扩展调色板、增加精灵数量和视差滚动效果。该项目需要从另一台 NES 主机中拆解组件，具体包括一个额外的 PPU、地址锁存器和多路分配器。硬件组装过程包括在 6x8 厘米的原型板上制作定制电路板，并将修改后的多路分配器插座安装到主机的母板上。完成后的双 PPU 组件通过安装在原 PPU 位置的排针进行连接。由于物理改装过程复杂，作者指出相关文档可能不够详尽。对于希望在不进行焊接风险的情况下尝试此配置的用户，可以使用 Mesen2 模拟器的定制分支版本。仓库中包含完整的硬件 KiCad 文件，以及技术演示和双 PPU 图形增强效果的视频链接。

一个名为“高级任天堂娱乐系统（ANES）”的项目在 Hacker News 上引发了关注，其核心在于一项雄心勃勃的硬件改造：为标准 NES 添加了第二个图像处理单元（PPU）。讨论的焦点集中在这一改造的技术影响上，用户们对在真实硬件上扩展系统原有功能的能力感到着迷。评论者推测任天堂为何未能在原始主机中利用这些未启用的功能，并提出这究竟是“过度设计”还是基于成本与实用性的权衡。尽管一些用户回顾了自己年轻时对主机进行超频的经历，但 ANES 项目因其对系统提供了切实改进，并有望解决精灵闪烁和运行缓慢等长期存在的性能问题，而受到了广泛赞誉。该改造的视频演示已经发布，激发了复古游戏爱好者的浓厚兴趣，他们急于了解该硬件在原有设计之外的潜能。

原文

This repo outlines the process for modding the NES to use 2 PPUs for advanced graphical features. I don't expect anyone to actually bother building this so the docs might be kind of half-assed at times. Check out my modified fork of Mesen2 if you'd like to play with this concept without modding your NES. See the related projects section for some demos that take advantage of the dual-PPU setup.

Watch the video!

More colors!
More sprites!
Parallax scrolling!

KiCad files can be found in the hardware directory.

You'll want to start with two consoles. One to modify and another as a parts donor.

quantity	location	part number	description
2	U1, U2	RP2C02	PPUs desoldered from both consoles
1	U3	AS6C6264-55PCN	Static RAM for PPU2
1	U4	74LS373	Address latch desoldered from donor console
1	U5	74LS139	Demultiplexer desoldered from donor console
1	U1	EMS-26405	40 pin wire wrap socket for PPU1
2	J1		20 pin female pin headers to receive the wire wrap socket
1	U5/J3		16 pin socket for 74LS139
4	RN1		10K 1/4 watt EXT pull down resitors
1			6x8cm prototype board
1	U2		40 pin socket for PPU2 (optional)
1	U3		28 pin socket for AS6C6264-55PCN (optional)
1	U4		20 pin socket for 74LS373 (optional)

The 6x8cm prototype boards listed in the materials section is slightly too large and interferes with the expansion port.

2. Desolder the Following

RP2C02 (U5) from the console you want to modify and your donor console.
74LS373 (U2) from your donor console.
74LS139 (U3) from your donor console.

These capacitors may be in the way of the dual-PPU board.
Fold them down flat or relocate them to the other side of the motherboard.

Solder 2 20 pin female headers where the PPU used to be.

5. Build the Dual-PPU Board

Follow the provided schematics and photos to assemble the dual-PPU board. Good luck.

4. Install the Demultiplexer

remove pins 6, 7, 9, 10, 11, 12, 13, 14, and 15 from a 16 pin IC socket. Bend pins 2, 3, 4, and 5 out horizontally. Attach the socket on top of the console's 74LS139, soldering the remaining pins 1, 8, and 16. Solder a jumper wire from pin 2 of the socket to CPU address line A12
Solder a jumper wire from pin 3 of the socket to the console's 74LS139 pin 5
Solder a jumper wire from pins 4 and 5 of the socket to the /CE pins of PPU1 and PPU2 respectively.
Install your donor 74LS139 in the socket.

5. Install Dual-PPU board

Plug the dual-PPU board into the female pin headers. You're done.