PPU warmup is real

Discuss technical or other issues relating to programming the Nintendo Entertainment System, Famicom, or compatible systems. See the NESdev wiki for more information.

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BMF54123
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Post by BMF54123 »

Mine tends to fail if I don't play it for a long period of time, though this is likely an entirely different issue. :(
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aquasnake
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Re: PPU warmup is real

Post by aquasnake »

Through executing the delay code in pre boot header, and then the instruction jump to the reset vector to achieve soft reset, it will have a better effect on some games with insufficient PPU warm-up time.

To put it simply, a multi-cart with menu header which can choose to enter a certain game (even though there is only one game loaded by menu header) makes the program more robust

Based on the conjecture of hardware design, perhaps the internal reset delay time of PPU is longer than that of CPU. When the CPU is executing the startup code, the PPU is not ready. At this time, even if some PPU registers have been written, they will be cleared by the internal reset process of PPU. Reasonable design should ensure that PPU is ready before CPU
puppydrum64
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Re: PPU warmup is real

Post by puppydrum64 »

I'm wondering if this is why Alfredo and Jigsaw (from Action 52) won't boot except on certain emulators (from what I understand those games don't run on the actual cartridge version either)
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rainwarrior
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Re: PPU warmup is real

Post by rainwarrior »

puppydrum64 wrote: Fri May 07, 2021 5:51 pm I'm wondering if this is why Alfredo and Jigsaw (from Action 52) won't boot except on certain emulators (from what I understand those games don't run on the actual cartridge version either)
No, the Action 52 startup menu already waits for the PPU to warm up long before you'd be able to select either of those games.
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