Neo Myth Menu beta

Chilly Willy · Post by **Chilly Willy** » Sat Dec 12, 2009 3:04 am

LocalH wrote:
Chilly Willy wrote:I also thought of something - when I made my progress bar, I added a sync to the vertical blank in the load routines to keep the bar from flickering. However, on a 4MByte rom, that adds almost 9 seconds to the load! I've disabled that, so the progress bar flickers during load, but you save a significant amount of time. Loading from flash is almost twice as fast on large roms, and from SD the time for 4MBytes dropped from 85 seconds to 76 seconds.
Perhaps you could spare a byte of RAM? Have the loading routine update it as necessary with a percentage value (obviously doesn't have to be 0-100, can be whatever you need to ease the implementation) and then have a small vsync routine that reads that value and updates the progress bar (if it doesn't break your load code to make use of Vints in such a way).

INTs have to be disabled while the Neo Myth is doing its thing since often the exception table at 0 disappears depending on the mode the Neo Myth is in. However, I think setting a variable that's updated during the vertical blank int during those times the ints are on should be doable. I'll see if I can't work that into a future update. Thanks for the suggestion.

LocalH · Post by **LocalH** » Sat Dec 12, 2009 4:33 am

Chilly Willy wrote:INTs have to be disabled while the Neo Myth is doing its thing since often the exception table at 0 disappears depending on the mode the Neo Myth is in. However, I think setting a variable that's updated during the vertical blank int during those times the ints are on should be doable. I'll see if I can't work that into a future update. Thanks for the suggestion.

Another suggestion: do you know what actually appears in the 68k vectors during these times when it "disappears"? Is it all 0's or is there some way the value found there could be exploited to bounce the PC to the normal Vint handler?

Chilly Willy · Post by **Chilly Willy** » Sat Dec 12, 2009 5:06 am

It could be any block out of the flash. No telling what data may be there. Depending on the "mode" the menu flash, the game flash, or the PSRAM in the Neo Myth can appear at 0. In my menu, the menu flash has valid int vectors, so no problem there, but when you are reading or copying the game flash, it could literally be anything at all. Once you copied a valid MD/32X game to the PSRAM, then the PSRAM will have a valid int vector table, but before that, it could be anything as well.

So most of the Neo routines are in the MD Work RAM and turn off the ints while doing there thing. That way you don't have to worry. Just don't cause any software exceptions!

Alex Khan · Post by **Alex Khan** » Tue Mar 02, 2010 5:37 pm

What's the Neo Myth all about I am totally Illiterate on the subject!

Chilly all I have learnt so far is there is a Stef kit and a Basi Compiler to create roms where does the Neo Myth fit into this Sega Homebrew Puzzle?

Chilly Willy · Post by **Chilly Willy** » Tue Mar 02, 2010 6:20 pm

Alex Khan wrote:What's the Neo Myth all about I am totally Illiterate on the subject!

Chilly all I have learnt so far is there is a Stef kit and a Basi Compiler to create roms where does the Neo Myth fit into this Sega Homebrew Puzzle?

It's one of the available flash carts for the MD. There are four you can get right now: the Neo Myth, the MegaCart, the MD-Pro, and the Evermind-MD (which is new - there's a thread on it in the hardware forum). The Neo Myth is the most flexible, but also far and away the most expensive. The new Evermind seem to be the best value for your buck.

Flash carts are how you play homebrew on real hardware. Without a flash cart, you're stuck playing homebrew on an emulator like Kega.

TmEE co.(TM) · Post by **TmEE co.(TM)** » Tue Mar 02, 2010 8:16 pm

Only problem I see with NeoMyth right now is in the software to burn stuff on it... seems it does not like MD ROMs that do not say SEGa MEGA DRIVE or SEGA GENESIS in $000200, I have SEGA MD & GENNY in a lot of my stuff and the software whines about it and on the flashcart they're thought to be SMS ROMs then......

Chilly Willy · Post by **Chilly Willy** » Tue Mar 02, 2010 8:53 pm

TmEE co.(TM) wrote:Only problem I see with NeoMyth right now is in the software to burn stuff on it... seems it does not like MD ROMs that do not say SEGa MEGA DRIVE or SEGA GENESIS in $000200, I have SEGA MD & GENNY in a lot of my stuff and the software whines about it and on the flashcart they're thought to be SMS ROMs then......

You should try madmonkey's app. Anywho, you HAVE to have "SEGA" at $200 if you wish to be compatible with TMSS MDs. My own menu looks for an SMS header, looks for SEGA, looks for a couple other things, then assumes it's an "old" Genesis binary. Not sure what the Neo2 Ultra Menu does. If madmonkey's app doesn't work, you can at least change it as it's open source.

MottZilla · Post by **MottZilla** » Wed Mar 03, 2010 4:16 am

I ended up buying the Neo Myth MD cartridge to replace my Double Pro Fighter. It's true it's expensive, but it's pretty nice otherwise. Chilly Willy's Menu allowing SD card loading of Genesis/32X roms is really awesome.

Chilly Willy, do you think in the future your menu will be able to support loading SMS roms from SD card? Or is it just not feasible? One other question, does your menu support Super Street Fighter 2? I tried loading it a couple times and just got a red solid failed checksum type screen.

I definitely think for homebrew the Neo cart is great since popping your ROM on a SD card is alot less involved than the MegaCart or MDPRO. The new cart that also features SD looks nice and the price certainly is alot easier on your wallet. But I prefer the Neo still.

Chilly Willy · Post by **Chilly Willy** » Wed Mar 03, 2010 6:13 am

MottZilla wrote:Chilly Willy, do you think in the future your menu will be able to support loading SMS roms from SD card? Or is it just not feasible?

The only thing stopping us right now is figuring out how to properly write the "zip ram" in the Neo2-SD. Once that's figured out, you'll be able to run SMS from the SD card.

One other question, does your menu support Super Street Fighter 2? I tried loading it a couple times and just got a red solid failed checksum type screen.

I believe you need to patch that game to get it working... probably to disable that checksum. Not to sure about it since everyone uses the patched version.

I definitely think for homebrew the Neo cart is great since popping your ROM on a SD card is alot less involved than the MegaCart or MDPRO. The new cart that also features SD looks nice and the price certainly is alot easier on your wallet. But I prefer the Neo still.

The best part about the Neo Myth for homebrew is all that PSRAM on it. Without bank selecting, homebrew has 2 MB of contiguous ram for use. With bank selecting, all 8 MB is usable.

Alex Khan · Post by **Alex Khan** » Thu Mar 04, 2010 5:28 am

>>Flash carts are how you play homebrew on real hardware. Without a flash cart, you're stuck playing homebrew on an emulator like Kega.

I see ... yes I have noticed posts about people writing homebrew and wanting to test if it worked on real hardware or not.

I wondered if it worked on K Fusion then would it work on real hardware as well?

Aha so that's how homebrew games are played on real hardware!

Thank You Chilly that was very educational.

-A Question:
Now if I am testing my game on K Fusion or Gens and it runs correctly on either emulator then it will work on a flash cart.

But it working on actual hardware is a hit or miss?

Is my deduction correct Chilly or am I off the mark?

Shiru · Post by **Shiru** » Thu Mar 04, 2010 5:48 am

Testing on the real hardware is absolutely necessary. No emulators provide 100% emulation. They all are made to run existing software, there is absolutely no guarantee that they could run new software, which could rely on some hardware quirks (even if accidentally, not for purpose).

Besides of this, TV screen and encoded TV singal is very different thing from PC monitor, so graphics which is looks fine on PC could look bad on TV, and vice versa; TV screen also could crop the picture, so you could accidentally place some elements outside of safe area, if you testing your project using emulator only.

Stef · Post by **Stef** » Thu Mar 04, 2010 9:13 am

I would say that testing on emulator is faster and easier maybe, you could do it for fast testings purposes but at some point you will have to test on real hardware because as Shiru mentionned, emulators are less touchy than real hardware and they accept some quirks than real hardware won't...

Shiru · Post by **Shiru** » Thu Mar 04, 2010 9:54 am

Yes, I wasn't clear enough: testing on the real hardware is necessary, but you don't have to do it all the time. You could test the project in emulators most of the time, but you have to test it at least once on the hardware, before release. To avoid headache, you'd better to test the project on hardware more often, because otherwise you could miss the moment when your change in HW-related code leads to bug, which could be really difficult to locate later.

Chilly Willy · Post by **Chilly Willy** » Thu Mar 04, 2010 5:29 pm

Most programmers start with testing in an emu, then move to testing on real hardware after it seems okay on the emu. The most common error programmers do that slips by the emu is putting code or data on odd boundaries. With an emu, that usually works fine. With real hardware, it always generates an odd address exception.

Alex Khan · Post by **Alex Khan** » Fri Mar 05, 2010 7:02 am

Okay I am confused ... flash cart is not real hardware then?

So if it works on a FLash cart and an Emulator it may not work on real hardware?

Testing on real hardware is creating a cartridge for the MD???