Search found 475 matches

by Joe
Wed Jan 12, 2022 11:42 am
Forum: Other Retro Dev
Topic: DOS VGA Tricks
Replies: 51
Views: 24090

Re: DOS VGA Tricks

This is not going to work, documentation says it is used to calculate the start address at the top left of the screen, and it adds this to the start address register. What documentation are you reading? This very reliable source says the value you write applies at the start of the next line. (Scrol...
by Joe
Wed Jan 05, 2022 5:47 pm
Forum: Reproduction
Topic: NES PRG or CHR ROM Piggybacker adapters
Replies: 11
Views: 425

Re: NES PRG or CHR ROM Piggybacker adapters

Yeah, I traced how a handful of the flash ROM pins are wired and compared it to the Nintendo mask ROM pinout. It definitely goes component-side.
by Joe
Wed Jan 05, 2022 4:05 pm
Forum: Reproduction
Topic: NES PRG or CHR ROM Piggybacker adapters
Replies: 11
Views: 425

Re: NES PRG or CHR ROM Piggybacker adapters

You've attached them to the wrong side of the board. They're supposed to replace the mask ROMs.
by Joe
Fri Dec 31, 2021 4:23 pm
Forum: phpBB Issues
Topic: Difficulty logging in while using 4G
Replies: 7
Views: 450

Re: Difficulty logging in while using 4G

Does your IP address periodically change while you're using 4G? You might be hitting a security feature that wants your IP address to stay the same.
by Joe
Fri Dec 31, 2021 2:34 pm
Forum: NES Music
Topic: How do I translate SMB music data to a list of frequencies?
Replies: 2
Views: 169

Re: How do I translate SMB music data to a list of frequencies?

Is "d7" always the first hex value in those horizontal lists? I've taken a look through, and I don't see much of a correspondence if it equals a 1 or 0. It's talking about bit 7, the most-significant or leftmost bit of the byte. You can see if it's a 1 or 0 by converting the value to bina...
by Joe
Fri Dec 10, 2021 12:47 pm
Forum: Test Forum
Topic: A test post
Replies: 10
Views: 1069

Re: A test post

Test (469 to 470)

Edit: well, that worked perfectly fine. What broke to give this person a post count of 1?
by Joe
Thu Jun 17, 2021 4:21 pm
Forum: NESdev
Topic: Somebody is selling my game
Replies: 13
Views: 2175

Re: Somebody is selling my game

If you haven't given them a license to distribute your copyrighted material, what they're doing is illegal.

They might be willing to talk about it though. You can try contacting them before you start getting lawyers involved.
by Joe
Sat Jun 12, 2021 7:57 pm
Forum: Newbie Help Center
Topic: Questions About DPCM and PCM
Replies: 21
Views: 3526

Re: Questions About DPCM and PCM

I find it odd that it works if I put it before turning on the screen but not after. It's not odd at all. Right around where you turn on the screen, you also enable NMI. Your NMI handler doesn't preserve the contents of A/X/Y, so whatever code it interrupts will suddenly have different values in the...
by Joe
Tue Jun 01, 2021 9:37 am
Forum: Newbie Help Center
Topic: Creating a data structure.
Replies: 33
Views: 4253

Re: Creating a data structure.

I don't know C well enough to know what i am doing wrong... It sounds like you're building it inside the msys2 shell instead of the mingw32 or mingw64 shell. Each shell is associated with a specific toolchain, and the msys2 toolchain is dependent on msys2. The mingw32 and mingw64 toolchains produce...
by Joe
Mon May 31, 2021 10:53 am
Forum: Newbie Help Center
Topic: Creating a text box
Replies: 31
Views: 4336

Re: Creating a text box

I'm aware that the vBlank box is unchecked, that might have something to do with it. Only thing is any time I load $2002 the debugger shows the NES as having exited vBlank and I don't think that's how it works. The Vertical Blank checkbox reflects the state of the vertical blank flag in the PPU. Tw...
by Joe
Fri May 21, 2021 9:08 pm
Forum: Newbie Help Center
Topic: How should I code this?
Replies: 4
Views: 2698

Re: How should I code this?

Sorry for the title, don't really know what to call the thing I'm trying to do. Arctangent? If you have to pass these numbers to the function through memory, you might be able to leave their original values in memory and perform the comparisons after you've finished the calculations. Without seeing...
by Joe
Sat May 08, 2021 1:40 am
Forum: NES Hardware and Flash Equipment
Topic: A hypothetical MMC3-like mapper without a CPLD
Replies: 4
Views: 4096

Re: A hypothetical MMC3-like mapper without a CPLD

This is just for fun. You wouldn't build this thing if you're worried about how much it costs.

Although, you could replace the four 74*670 with eight 74*373 (or 74*573), a couple of 74*139, and... two 74*04, I think? Spend the money you save on cheaper parts to get a bigger board to hold all of them.
by Joe
Fri May 07, 2021 12:49 pm
Forum: NES Hardware and Flash Equipment
Topic: A hypothetical MMC3-like mapper without a CPLD
Replies: 4
Views: 4096

A hypothetical MMC3-like mapper without a CPLD

Reading about mapper design had me wondering just what it would take to build something like the MMC3 using only new DIP ICs. Turns out it's pretty easy once you have a GAL16V8 . PRG and CHR bank registers can be handled by a bunch of 74*670s. A single *670 can give you four 8KB PRG banks out of a 1...
by Joe
Sat May 01, 2021 5:37 pm
Forum: Reproduction
Topic: SNES VHDL mappers for CPLD
Replies: 3
Views: 3097

Re: SNES VHDL mappers for CPLD

Aren't SNES cartridge mappers pretty simple? If you're using 5V ROMs, you might be able to use a smaller 5V-tolerant programmable logic device, like the ones lidnariq suggested in this post.
by Joe
Thu Apr 29, 2021 8:33 pm
Forum: Newbie Help Center
Topic: Making a cart from scratch...
Replies: 75
Views: 28335

Re: Making a cart from scratch...

Is the AX5202P draining the battery? The wiki claims it's possible. If this is what's causing the problem, you'll see it as unusually high voltage drop across one of the resistors even with the RAM completely removed from the board. (I don't know how to check it without removing the RAM. I also don'...