SpritesMind.Net

That is a pretty nice writeup ~

Someone make me a 32X test ROM with same sort of grayscale ramp as seen here : viewtopic.php?f=22&t=2188

And while at it, play a full scale sinewave on both L and R side, I'll get the scope out and measure the levels at various points.

http://www.tmeeco.eu/SMD/Hardware_Inter ... 20Wiki.mht

I have been using that

68K duplicates high and lwo bytes during 8bit writes (i.e $12 is $1212 on the bus). Reads are aways 16bit and CPU internally chooses which half to use depending on address.

Computer composhit output would look nothing like the MD output (i.e near complete lack of various artifacts) and you still have the problem of non-linear level ramp that most emulators and tools don't treat right from what I know ( http://gendev.spritesmind.net/forum/viewtopic.php?f=22&t=2188 ). Th...

I haven't had any issues by doing a shorter than 192 cycle reset, but I always explicitly zero out all the YM registers and it seems internal state is also fine.

68K User manual suggests it is based on bus cycles rather than instruction cycles, I got the impression you can get the bus while an instruction is still halfway done. The processor asserts BG as soon as possible. Normally, this process immediately follows internal synchronization, except when the p...

There's 16 or 18 access slots spread around one line during rendering, depending on 256 or 320 pixel mode, each capable of accepting one byte so 16 or 18 bytes are possible to transfer in best case during a line. 4x 68K cycles is 3.5 pixels, these access slots come in triplets that are 16 pixels apa...

If it is a proper NOR flash it'll take more than 100k writes before the flash fails. Overall the idea looks doable but I'm not sure if you can cleanly supply NOPs to the 68K and later get it execute something more useful. If I were you I'd pull !MRES low (this signal you can drive yourself, but only...

Ok, so you support the Saturn stuff in your game ? How would the MD port pins be connected to the Saturn port ? I'm not sure any standard exists...

Use lowercase letters too not just uppercase ones, or perhaps just set the top bit to show it is saturn peripheral and not MD.

Atmosphere of mars is just incredibly thin, roughly 100x thinner than earth. If it was 100x denser you could even breathe it for a limited amount of time, while there's possibly enough oxygen to sustain you, there's far too much carbon dioxide and you will get a CO2 poisoning from it. The thiness al...

Composhit is always available, even if one uses RGB. In a proper cable the composhit line is used for sync info for example and also acts as fallback when TV isn't supporting RGB via the SCART. It is also trivial to get luminance info out of both composhit and RGB, and sync you always have side by s...

Faster CPUs, more RAM and just enhancing VDP and sound is far more useful and much more doable... getting the two sides share single cart is not going to happen more or less though just adding second VDP (and not doing DMA with it) can work out to some extent. It does take a significant FPGA to fit ...

FPGAs are the only solution, and stuff where you can fit substantial amount of things are easily 50€ a chip (but some simpler stuff can be done with the cheap 20€ chips), and you still need various other parts such as DACs, memories, connectors and also plastic, assembly and distribution. What is yo...