nesdev.org

So thinking along these same lines Came up with this
Yogi

There's absolutely no mirroring in the way you mention. Because the 74LS138 considers A14,A13 and A12 on it's logic, the YM2413 will be mirrored at the whole 9000-9FFF range. But then the FM synth inside the VRC7 mirrors in the exact same way. For 8000 we have A15=1 A14=0 A13=0 A12=0 and for 9000 w...

It's actually a lot simpler than what you thought: https://lh4.googleusercontent.com/-TF2TBkoqPt4/U8nLpInGBVI/AAAAAAAAHZE/_FeQkUuH4UQ/s800/FAMICOM2413.jpg (this is enough to make the YM2413 work properly without any side effects) And I have a feeling that the mapper is using internally a logic func...

I commented about the YM2413, because the small chip in the middle of the board happens to be a YM2413 which is connected to 0x9010/0x9030 and receives the same writes as the VRC7 FM core. It's operating properly and produces music without distortion or wrong sounding notes. (save the rom patches b...

I was thinking of getting a LGP famicom cart but didn't want to lay out the cash for it and a Fami-to-NES adaptor ATM. If you're already up for rework, Tiny Toon Adventures 2 is a little bit cheaper on ebay. (Looks like ~$28 instead of ~$35) I knew it used the VRC7 mapper but does it have a functio...

My hardware has a socket for CHR ROM but it has a CHR RAM (32Kb banked) piggy backed on the solder side of the board. A pair of switches toggle A18 on/off (when off it puts the pin 31 at +5v which is ideal for 256 or 128Kb flash chips) and CHR ROM/CHR RAM mode. The cart can run Lagrange Point as it...

My current idea is put the driver code *too* at the fixed page (we can have two different source codes as it won't be too much of a hassle) and we use the songs as .asm includes. That is how I handled it. The CHR data, Reset and a part of the NMI code are in two 8K banks (we lose 16K for these). Du...

Man let's work together so we don't need to do all the work twice ! :D VRCVI: http://www.youtube.com/watch?v=PxXf0KBTvnI http://www.youtube.com/watch?v=Pgu7l_XpE1A The VRCVI hardware is just a Madara cart with holes and sockets for eproms/eeproms. It was modified to use INES 24 registers layout. VR...

tepples wrote:What I do is read the controllers twice, and if they don't match, use the previous frame's data. A tested example is in pads.s in this project template.

Thanks tepples! I'll follow your example. Such a weird thing!
Yogi

I can confirm that the glitches are due to DPCM samples. I added a folder to the Dropbox on the first post, which has a .NES rom and the User Configure.asm (Disclaimer: none of the songs used are my work, all have been DLed from FT Fourm). To test, I edited a FTM file and exported the song with two ...

Same sort of timeline with my son, seems a few Xbox games are portable but most are not. Not sure about the HD issue, but could be due to the need to patch the old code to run on the new system, if there is a patch
Yogi

A false controller read due to a DPCM could account for the behavior but I doubt that Nestopia emulates the hardware this closely. Nestopia does emulate this glitch behavior. Wow, did not realize. This sheds a new light on things. Will have to investigate this more; had assumed it was due to differ...

Just to let you know, Vegaplay code for pad reading has that problem with DPCM DMA transfers causing false positives to button presses. For obvious reasons this is actually a SERIOUS problem considering that DPCM will be used extensively within the music playback code. To fix it I had to change thi...

This sounds promising. The limitation of songs in Vegaplay has been a problem for me. Same here, it was my motivation. I hope it will be useful, if people would like a 512K build it's not too much of an issue. The main thing I wanted was a 'no fuss' tool to put music on real hardware. I haven't cha...

So here is a project that I've been working on. It's a SNROM version of VegaPlay. With a 256KB flash you can load 7 non-banking NSFs <32K (you lose the vector table and trampoline bytes from each 32K 'slot'. One 32K 'slot' is used for reset code and CHR data that's banked out after reset.). The runt...