What's the target system that you're writing this player for? I ended up writing a converter and a custom MOD player. Basically re-arranging some stuffs so that they are speedier and such. The player code I wrote, is too specific to the system to really use for anything else - even if it is 65x ...

The ASL assembler supports the Mitsubishi 65x variant: http://john.ccac.rwth-aachen.de:8000/as/

Apparently from looking over the doc for the assembler, there's also a 16bit version of the original 740. But that's all I know about it.

The SPC700 cpu in the Sony audio unit for the SNES, also ...

Overall, if you're looking for anything resembling performance, you'll want either a discrete component CPU (using actual TTL parts)

That's on my list to do one day :D That would be a ton of fun. Nothing serious mind you, just a hobby project.


I was digging around in a binder the other day ...

Came across this during some random search - http://homepage.mac.com/jorgechamorro/a2things/PDFs/65xxx.txt

I've never heard of the 6516 mentioned before (as a development pursuit or otherwise). The 6516 sounds pretty impressive from what's mentioned in that article. Out of the handful of ...

hi there,
i have so far completed all addressing modes, instructions, the routine of fetching opcodes, push/ pop. So in short if i load a game into my emulator, it verifies the nes format, then fetches code and executes instructions etc.
The problem is that upon fetching the first instruction which ...

http://nesdevwiki.org/index.php/NESdevWiki

The rom header will indicate if the game (not just the mapper) supports additional SRAM (mapped to $6000-$7fff). Be careful, some older iNES formats have incorrect headers. You can tell by search for 4 different identifiers in the second half of the $10 ...

And I take it the 65c02 or 65cs02 do not have buffers on the processor side to protect from another device trying to drive the same address bus? (not necessarily tri-state)

Like if the processor is halted via /RDY and the address bus has a random (but static while paused) value asserted by the CPU ...

Unfortunately, in the Atari XL/XE line, there is now easy way to replace the NMOS 6502 for a CMOS one, because the Atari 6502 has this special "halt" signal for sharing the bus with Antic.

Shouldn't /RDY be a replacement to halt? You can pause the CPU as long as you need with /RDY if I recall ...

I agree. One thing I've done when writing self-modifying code is only make one change at a time from non-self-modifying to self-modifying, then test that change. Then, if it goes off into the weeds and pretty much clobbers everything in RAM (hey, it happens :)), I know where to look, and it's ...

This might interest some of you.

http://www.ic2ic.com/search.jsp?sSearchWord=HUC6260&prefix=H

http://archaicpixels.com/index.php/HuC6260


It generates RGB and NTSC signals, has a 9bit pixel bus, 9bit data bus, 3bit red/green/blue for a total color count of 512colors, and a 512 color palette ...

The original reason I gave up on self-modifying code was the idea of then trying to unpick where code has gone wrong - if it's not what I originally wrote, I not only have to figure out why it failed, but also how it modified itself before it failed :(

To be honest I see no difference between ...

Correct- anything above 15.7khz is technically down sampled since you're losing some resolution the further/higher up from 15.7khz you go.

Why don't you explain what you're doing?

You can start wth how you get a 32khz output frequency
with a 15.7khz sample rate ;)

You can playback a sample at 32khz(31470hz) on a 15.7khz by skipping every other byte. It's like scaling a bitmap scanline on a fixed resolution display, but the ear ...

I've been writing a ton of self modifying code for optimizations on my latest project. Probably the largest amount I've written in a single project. The combinations of LUTs and self modifying code really makes for some really fast code. I did a search and didn't find a topic specifically on this ...

I got the frequency scaler up and working. Just a simple fixed point math LUT. The 8bit whole number + 8bit float are the counter for reading the sample data to the DAC (or a buffer for DMA). I made a 100hz increment table from from 0khz to 32khz divided by my output frequency of 15.7khz (using the ...