Search found 1135 matches

by Ben Boldt
Fri Sep 30, 2022 8:19 pm
Forum: NES Hardware and Flash Equipment
Topic: Developing cheap FPGA replacements for NES CPU & PPU?
Replies: 10
Views: 756

Re: Developing cheap FPGA replacements for NES CPU & PPU?

That’s a good point. It may be written more like an emulator that runs on a computer. I would highly doubt that it is doing all of the normally redundant PPU fetches for example. I don’t know this for sure but it sure seems like this is a lot more than just “hooking things up”; more like a complete ...
by Ben Boldt
Fri Sep 30, 2022 1:36 pm
Forum: NES Hardware and Flash Equipment
Topic: Developing cheap FPGA replacements for NES CPU & PPU?
Replies: 10
Views: 756

Re: Developing cheap FPGA replacements for NES CPU & PPU?

Individualised wrote: Fri Sep 30, 2022 1:26 pm I'm sure that the NES core developed for it could be retooled to allow the creation of dedicated FPGA CPUs and PPUs, it does seem like it's an adaptation of something else itself.
Yes, great idea. Basically connecting everything with I/O pins instead of internally, but still using the same core.
by Ben Boldt
Fri Sep 30, 2022 1:07 pm
Forum: NES Hardware and Flash Equipment
Topic: Developing cheap FPGA replacements for NES CPU & PPU?
Replies: 10
Views: 756

Re: Developing cheap FPGA replacements for NES CPU & PPU?

That looks like a whole entire Famicom system, which is really cool. But that looks like a self-contained thing that runs ROM files only from SD card and does not accept cartridges. The OP (and myself) want something to replace the PPU and/or CPU in an existing NES/Famicom system. So it still runs f...
by Ben Boldt
Thu Sep 29, 2022 2:26 pm
Forum: NES Hardware and Flash Equipment
Topic: Developing cheap FPGA replacements for NES CPU & PPU?
Replies: 10
Views: 756

Re: Developing cheap FPGA replacements for NES CPU & PPU?

I think it would be great if there was an open source FPGA NES CPU and PPU. Especially for the PPU, to get RGB output. This would not necessarily blow away all of the closed-source ones, especially as those have unique features such as video filters, on-screen configuration, CPU speed adjustment, et...
by Ben Boldt
Wed Sep 28, 2022 9:32 pm
Forum: Homebrew Projects
Topic: Black Jewel Reborn [NES]
Replies: 13
Views: 1836

Re: Black Jewel Reborn [NES]

Recommendation: You should do parallax scrolling for the mountains.
by Ben Boldt
Sun Sep 25, 2022 8:13 pm
Forum: Homebrew Projects
Topic: Grid floor tech demo
Replies: 2
Views: 333

Re: Grid floor tech demo

Think what you could do with this with 2 PPUs. Seicross definitely comes to mind.
by Ben Boldt
Fri Sep 23, 2022 5:33 am
Forum: SNESdev
Topic: Replacing 7805 with RECOM 78B50.5-1.5
Replies: 3
Views: 361

Re: Replacing 7805 with RECOM 78B50.5-1.5

Why did you replace it? The new one might need different caps than the old one.
by Ben Boldt
Thu Sep 22, 2022 9:50 am
Forum: NESdev
Topic: Gameplay actions that don't need to be done every frame
Replies: 7
Views: 545

Re: Gameplay actions that don't need to be done every frame

Music would tend to work well at a lower update rate. If you were trying to do something like vibrato, you may start to hear it becoming "pixelated", which may or may not be a good thing (usually not).
by Ben Boldt
Wed Sep 21, 2022 1:58 pm
Forum: NESdev
Topic: Does 30 fps look too uncanny for a retro style game?
Replies: 14
Views: 847

Re: Does 30 fps look too uncanny for a retro style game?

Is it possible for your program to become aware of dropped frames and throttle back dynamically? Then you could have a dynamic framerate that could even drop multiple frames at a time if necessary. Not sure I have ever seen this done on an NES. Everything would have to be coded such that it could ad...
by Ben Boldt
Tue Sep 20, 2022 10:49 pm
Forum: Newbie Help Center
Topic: About the MMC3 Mapper and Address Conversions
Replies: 4
Views: 401

Re: About the MMC3 Mapper and Address Conversions

Honestly I haven’t used Mesen much. It looks like the top row of the call stack shows the ROM file address. Fceux has a checkbox, that is what I was thinking of. I don’t see anything like that in Mesen. Edit: Oh I found it. It is code -> prg address display. That shows the ROM address on every line ...
by Ben Boldt
Sun Sep 18, 2022 9:39 am
Forum: Newbie Help Center
Topic: About the MMC3 Mapper and Address Conversions
Replies: 4
Views: 401

Re: About the MMC3 Mapper and Address Conversions

There isn’t a 1 size fits all conversion. It is confusing that you use the term PC, because that often means “program counter”. You are wondering the conversion from ROM address to CPU address. First of all, there is usually a 16-byte “iNES” header added to the ROM file. So, ROM addresses are always...
by Ben Boldt
Mon Sep 12, 2022 12:27 pm
Forum: NESdev
Topic: any way to change controls of functions
Replies: 3
Views: 577

Re: any way to change controls of functions

Welcome back kelvin. It has been a long time since we heard from you. You can use a debugger to find where the game reads the controller registers. The register reads 1 bit at a time from the controller. Most games shift these bits into a variable. Often times, the game will do it twice in a row due...
by Ben Boldt
Wed Aug 31, 2022 9:05 pm
Forum: NES Hardware and Flash Equipment
Topic: iNes mapper 163 vhdl code for XC9536???
Replies: 29
Views: 9087

Re: iNes mapper 163 vhdl code for XC9536???

Can you read a known-unprotected CPLD? If you can do that then just try the exact same thing with this one.

Why not just start from scratch? Then it’s actually yours. It doesn’t seem like a very complicated mapper.
by Ben Boldt
Tue Aug 30, 2022 4:22 pm
Forum: NESemdev
Topic: DOS Emulator with Debugger / Memory View
Replies: 29
Views: 1369

Re: DOS Emulator with Debugger / Memory View

Even with modern tools, it would be a pretty big undertaking to make the Game Genie code book. It kind of amazes me how that book could exist back then. Nowadays, we typically watch for RAM changes to find cheats. We find the RAM location that represents the number of lives left (for example). And w...
by Ben Boldt
Tue Aug 30, 2022 1:39 pm
Forum: NESemdev
Topic: DOS Emulator with Debugger / Memory View
Replies: 29
Views: 1369

Re: DOS Emulator with Debugger / Memory View

How do you suppose Galoob developed game genie codes? I am not sure they could have even used an emulator at that time. It might be interesting to go down that path.