Search found 216 matches
- Thu Mar 21, 2019 1:11 am
- Forum: NES Music
- Topic: Blargg's saw wave DPCM IRQ demo in NSF2
- Replies: 1
- Views: 7956
This is quite a significant development. The implementation of the things like SuperNSF and Deflemask drivers could become much better organized by using the cycle-IRQ feature.
This would be nice; I tried to do this a few years back but got hung up on some things. As for merging it into asm6f, I wouldn't be against it, but a decent way to set the target would be needed. (Probably best discussed elsewhere when the time comes.) That is basically why I said "soon", but didn'...
Thanks for the replies, I will see what I can get out of the audio knowing the fact that there really isn't a good way to avoid that phase misalignment... (except for that 1 in 32 chance where it will like up perfectly with the wave phase). I have since made a small fork of the open source ASM6 to s...
- Thu Mar 14, 2019 12:44 am
- Forum: Other Retro Dev
- Topic: PC Engine specifics
- Replies: 21
- Views: 25732
Dear all, thank you for the responses, they are all extremely helpful, so I need to make sure to save these specifics for the future, especially the transfer instructions clobbering the X and Y registers, which I would've no doubt run into otherwise. I wouldn't be surprised if ST0, ST1, and ST2 clob...
Hi, I have a growing interest in working with the PC Engine, and having read the most common documentation out there (MagicKit, MagicEngine, etc.) I have a few fairly specific questions that I could not find the answers to. I suspect that the system has not been torn to shreds as much as the NES, so...
- Sat Feb 02, 2019 5:16 am
- Forum: Other Retro Dev
- Topic: PC Engine waveform channel updates
- Replies: 8
- Views: 19532
I have since tried to do the same on the FDS, a system where I know that the channel has to be halted and reset to change the waveform, and the results are oddly clear with very little artifacts added. This is a promising next step.
- Sat Jan 05, 2019 2:32 am
- Forum: Newbie Help Center
- Topic: Help understanding sprite-0
- Replies: 23
- Views: 7859
A slightly less complicated, but also less effective way to "get more colors" is to use the PPU color emphasis bits . It's not nearly as useful as an actually changed palette, but it lets you get a few more tones (or a few washed-out colors by combining them with the grayscale bit) out of your alrea...
As it turns out, my original guess of being able to save 100-150 cycles was an extremely generous assumption. Currently, in the middle of redesigning the PCM code to accomodate this interpreter, it seems that the interpreter needs to be aware of how many cycles it has to spend before it has to retur...
- Tue Nov 20, 2018 1:57 am
- Forum: SNESdev
- Topic: Need sound help emulating NES on SNES
- Replies: 33
- Views: 25677
Some games do attempt to silence the triangle channel in weird ways that might cause some issues: - Mega Man and Mega Man 2, plus other Capcom games from around that time silence the triangle by writing 0 to the period register, some even use $4015 afterwards, it's really odd, but it makes a popping...
- Wed Nov 07, 2018 5:16 am
- Forum: Newbie Help Center
- Topic: Trying to understand PPU Registers
- Replies: 15
- Views: 6487
Your decoder has to look at the right bits (pins) to determine when to enable the peripheral and allow traffic between the CPU and the peripheral. My super simple 64kB PRG ROM setup requires a 1-bit register to select which 32kB half of the ROM I want the system to see at $8000-$FFFF. Since $8000-$F...
Possible tasks that could be made to run in constant time: * Filling buffers for scrolling * Filling buffers for sprites Thanks for the ideas. Thankfully I wouldn't even have scrolling updates because the rooms would be non-scrolling screens with fadeouts for transitioning, where the game draws the...
I have a long-going project to use the DMC IRQ to stream PCM data at 8.2kHz while still having enough time to run a game (with the tasks spread out across two frames for 30FPS). However, this is done by sitting around in the IRQ handler so that I can land another $4011 write right in between two IRQ...
- Fri Oct 05, 2018 1:33 am
- Forum: NESdev
- Topic: Problem converting 256 KB MMC-1 to 512 KB MMC-1
- Replies: 55
- Views: 15129
That makes sense, it's a way to assess how far people have come with reverse-engineering the hardware if you try to stick to the same limits on hardware as developer X, but you are still able to do more thanks to discoveries since then, and more time to spend on managing the available resources bett...
It just happens too often that you accidentally end up using zero page memory access instead of an immediate value. Had the 6502 assembly language been originally developed to require you to prefix both immedate values and memory accesses, this kind of mistake would slip through much less often. Whe...
- Wed Oct 03, 2018 7:24 am
- Forum: NES Graphics
- Topic: what does 8 bit graphics mean
- Replies: 43
- Views: 32575
When someone says NES "framebuffer", I immediately think of Videomation and Oeka Kids , which are designed to store a full screen framebuffer in CHR RAM. After that, I think of pseudo-framebuffers as used in Qix , Hatris , the Block Out prototype, 3D Block , and the like. If I'm not mistaken, it co...