Search found 11429 matches

by lidnariq
Sun Dec 03, 2023 1:37 pm
Forum: NES Hardware and Flash Equipment
Topic: Adding 64kb (32x2) WRAM into MMC5 ETROM board help
Replies: 23
Views: 4295

Re: Adding 64kb (32x2) WRAM into MMC5 ETROM board help

Theoretically all you should have had to do was:
hook up A13 and A14 from the MMC5 to both RAMs
adjust the solder jumpers q.v. to battery-back both RAMs
by lidnariq
Sat Dec 02, 2023 11:00 am
Forum: NES Hardware and Flash Equipment
Topic: Adding 64kb (32x2) WRAM into MMC5 ETROM board help
Replies: 23
Views: 4295

Re: Adding 64kb (32x2) WRAM into MMC5 ETROM board help

Was the donor NES-ETROM or HVC-ETROM ?
by lidnariq
Tue Nov 28, 2023 1:45 pm
Forum: Other Retro Dev
Topic: Some 5th Gen SDK Tips
Replies: 12
Views: 4469

Re: Some 5th Gen SDK Tips

Specifically for N64dev, I'd recommend using either the new "libdragon" toolchain - they provide instructions on how to compile your own - or if you want the leaked commercial-era SDK, it's been recompiled for modern gcc and you can find it as "modernSDK".
by lidnariq
Tue Nov 28, 2023 1:41 pm
Forum: NESdev
Topic: GTROM self-flashing issue
Replies: 6
Views: 1849

Re: GTROM self-flashing issue

I don't see how that poll routine ever worked :( As to how it might have accidentally worked - the total overhead (JSR to RTS) is 24 or 26 clocks (depending on whether there's page wrapping), which is 13.5µs, which is the "typical" byte-program time according to the SST39SF family. Still,...
by lidnariq
Thu Nov 23, 2023 8:10 pm
Forum: General Stuff
Topic: Did NTSC-J always use 0 IRE black level setup?
Replies: 8
Views: 3848

Re: Did NTSC-J always use 0 IRE black level setup?

Yup, that's what I'm saying.
by lidnariq
Wed Nov 22, 2023 6:35 pm
Forum: General Stuff
Topic: Did NTSC-J always use 0 IRE black level setup?
Replies: 8
Views: 3848

Re: Did NTSC-J always use 0 IRE black level setup?

The N64 is entertaining, because earlier revisions (with separate VI-to-RGB and RGB-to-composite chips) use 0IRE, and later revisions use 7.5IRE. This has no correlation - even a slight anticorrelation due to the later PAL launch - with physical consoles released in each of PAL-B&c, NTSC-J, PAL-...
by lidnariq
Mon Nov 20, 2023 4:01 pm
Forum: NESdev
Topic: 6502 SBC and NES Clocking
Replies: 20
Views: 3966

Re: 6502 SBC and NES Clocking

I've heard anecdotally that some modern famiclones are CMOS and use a 65C02 core. Unfortunately, I haven't heard of any research about which.
by lidnariq
Sun Nov 19, 2023 5:33 pm
Forum: NESdev
Topic: 6502 SBC and NES Clocking
Replies: 20
Views: 3966

Re: 6502 SBC and NES Clocking

To generate higher-resolution video, you'll be able to use a simple linemultiplier (e.g. one scanline in, two scanlines out) but NTSC used a substantially more underscanned video (220-ish scanlines active out of 262 - 84%) than almost all modern video standards (usually 90-97%). If you want to fix t...
by lidnariq
Thu Nov 16, 2023 11:48 am
Forum: NES Graphics
Topic: Nintendo/Ikegami's 80s Arcade graphics chip?
Replies: 26
Views: 6143

Re: Nintendo/Ikegami's 80s Arcade graphics chip?

Drag wrote: Wed Nov 15, 2023 10:28 pm Fun fact, Commodore was trying to shop both their VIC chips around and just nobody was biting at that time, [...] Both were designed specifically with video games in mind, rather than as computer displays.
The VIC-1 was designed for video games? Even though it only has a tilemap?
by lidnariq
Wed Nov 15, 2023 8:43 pm
Forum: NESdev
Topic: Question About the MMC1
Replies: 25
Views: 6316

Re: Question About the MMC1

Very few mappers provide a deterministic bank on power-on; only slightly more provide the ability to bank 32KB at a time. Those that do are most often multicart mappers, to ensure that the menu is selected on reset. Note that MMC1 does not provide a deterministic bank on power-on. (It was clearly in...
by lidnariq
Wed Nov 15, 2023 7:45 pm
Forum: NESdev
Topic: Question About the MMC1
Replies: 25
Views: 6316

Re: Question About the MMC1

Is there a reason you want to use MMC1? Almost all other mappers are better choices. I used the MMC1 because it's the simplest ROM mapper I could use for such a small task, like I said in my original post. I promise you, despite MMC1 having the lowest mapper number, it is far from the "simples...
by lidnariq
Wed Nov 15, 2023 5:52 pm
Forum: NESdev
Topic: Question About the MMC1
Replies: 25
Views: 6316

Re: Question About the MMC1

You don't know what the contents of the $E000 bank are on power-up: nothing is guaranteed. That's why the MMC1 provides the ability to reset banking to 16+16F mode in one instruction.

Is there a reason you want to use MMC1? Almost all other mappers are better choices.
by lidnariq
Wed Nov 15, 2023 12:28 pm
Forum: NES Music
Topic: Can we "Snooze" the 2a03?
Replies: 6
Views: 1889

Re: Can we "Snooze" the 2a03?

Z-saw has already been used publicly; it seems to close-enough-to-ready-to-use: https://github.com/zeta0134/z-saw/
by lidnariq
Tue Nov 14, 2023 12:37 pm
Forum: NES Music
Topic: Can we "Snooze" the 2a03?
Replies: 6
Views: 1889

Re: Can we "Snooze" the 2a03?

To answer the exact question you asked, unlike both the AY and the SN76489, the NES doesn't provide the ability to leave a channel just at DC "on" - you can't "snooze" the hardware oscillators. You still can bit-bang volume control on the NES, like almost every chip. If I had to ...
by lidnariq
Sun Nov 05, 2023 10:36 am
Forum: Newbie Help Center
Topic: 6 color palette, looking for advice.
Replies: 25
Views: 4407

Re: 6 color palette, looking for advice.

On a CRT, it is absolutely vital to make sure that the two fields are as closely matched in brightness as possible. Failing to do so will be noticeable and ugly.