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  • Joined: 12 Mar 2021
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under4mhz games
Post Posted: Mon Mar 15, 2021 11:08 pm
Hi folks!

It's been soooooo long the last time i've logged/posted and i'm happy to be back! :)

I have brought recently a Master Everdrive and it's so great that i can finally test and play all the new homebrews and conversions (MSX2SMS, GG2SMS).

But sadly, there is a few homebrews for the SG-1000 made by under4mhz that doesn't work with the Everdrive and especially in a real SG-1000, which is regrettable as i like very much under4mhz homebrews. I know we can play them with many emulators out there but playing a game/homebrew on a real game console is the best experience.

So here's a couple of pictures i took with the everdrive:












And just to be sure, i have burned on an eprom the Klondike game just to see if it's the everdrive and here's some pics:





And sadly, it's not the everdrive :(

Hopefully that under4mhz will be able to fix his homebrews so that they can play on a real SG-1000. ;)

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Post Posted: Tue Mar 16, 2021 8:14 am
Did you use the fixed version of Snake? The original version was having issues which I suspect to also be present in the other games
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Post Posted: Tue Mar 16, 2021 1:47 pm
Hi Calindro,

Yes i did, all the version are the latest ones. All his games works well with emulators but on a real console (eprom or everdrive), all i get is what we see in the pictures i took.

There is one picture that doesn't belong with the rest, it's the picture of Palikat. This one is to show that it works with the everdrive and also on the real console with an eprom. All other homebrews works well with the everdrive except the ones from under4mhz and the first two homebrews by Maechiko (Omikuji & S_Sniper)




And for Skyfox, the intro and text intro are OK but when you start a game, there's missing sprites but i suspect that game needs at least 2k of RAM since helmha told it was meant for the SC-3000 (as the SC-3000 has 2k of RAM and the SG-1000 has only 1k of RAM). The pictures showned are with an eprom on an SG-1000 as playing the game with an Everdrive, it works like a charm.





All the tests are done with a Master Everdrive on a Sega Master System or on an eprom on an SG-1000 as i'm still waiting for my SMS-to-SG-1000 adapter.
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Post Posted: Wed Mar 17, 2021 1:30 am
Wow. Thanks so much for your hard work.

I had an issue in my image decompression routine where I was writing too quickly to the vdu. This in turn effected uploading the tiles to the vdu for all my games. I haven't got any hardware to test it, so I didn't check if it worked on real hardware.

But I've (hopefully) fixed the problem. Attached is a copy of my games with the fixes.
Under4MhzPack-1.00.zip (358.98 KB)

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Post Posted: Wed Mar 17, 2021 10:28 am
I tried all your update on real hardware.

All SG games have a garbage screen before under4mhz logo that display for half a sec.

Both versions of Arno Dash seems fine.

For both versions of Arno Dash 2, the SFX when you die seems to bug.

Klondike/Mahjong Solitaire have a bit of garbage in-game for the SG version, and a display bug for the SMS version when you move a card/domino.

Pegged have a bit of garbage in-game for the SG version, and a display bug on title screen when you choose level on the SMS version.

Both versions of Pitman seems fine.

Snake SMS have garbage screen. Snake SG seems fine.

Vexed have a bit of garbage screen on both version.
 
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Post Posted: Thu Mar 18, 2021 4:52 am
Thanks Revo for all the testing you've done. Good work.

I can't see most of the problems on the emulators, so I've tried to fix the problems you've listed from reviewing my code.

(Attempted) fixes:

- Logo garbage (clear the vdu on startup)
- Pegged garbage in game (more nops on tile render)
- Pegged title bug (clearing with the wrong tile)
- Snake SMS (more nops on maze load)
- Mahjong/Klondike garbage and tile move (more nops on card rendering and vram to vram copy code)
Under4MhzPack-1.01.zip (358.79 KB)

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Post Posted: Thu Mar 18, 2021 12:17 pm
Ok so now no more garbage screen on SG version before under4mhz logo, just a green stripe (not a big deal).

The SFX of Arno Dash 2 still bug sometimes.

Both Klondike have same bug than before.

Pegged is fine on SMS, still bit of garbage on SG.

Snake still have some garbage when you press start on SMS version but it's a bit better.

Both Vexed have same bug than before.
 
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Post Posted: Fri Mar 19, 2021 1:22 am
under4mhz wrote
Wow. Thanks so much for your hard work.

I had an issue in my image decompression routine where I was writing too quickly to the vdu. This in turn effected uploading the tiles to the vdu for all my games. I haven't got any hardware to test it, so I didn't check if it worked on real hardware.


No problem and glad to help out in any way. ;)
.
You don't have any hardware to test out your games ? Well, getting an SMS varies between $50 and ??? (local marketplace, flea markets, etc) and getting an Master Everdrive is about $40 and since you are developping on both SG-1000 and SMS, go with the SMS since it's also SG-1000 compatible. I have a SMS, SG-1000 and a Dina 2-in-1.

20 years ago, me and Daniel (now Amy) Bienvenu did a game for Digital Press called Ms.Space Fury and i have made a Colecovision test cart so we could see if they were any difference between emulation and real hardware. Often, both were the same but time to time, we have seen major bugs on a real Colecovision but nothing on any emulator.

Even if emulators now are way better than 20 years (heck yes!), there will always have a difference between emulation and real hardware.

Ok now, i have tested all your SG-1000 games version and here's some pictures (reduced by 75%) to show you how they look like:





Arno Dash 1 looks perfect!




Also Arno Dash 2 looks perfect!








Klondike is almost prefect but has some tiny bugs. If you check picture 4, you can see a few tiny lines on the sides and on picture 5, don't know if the King of Heart is supposed to look like this.





Pegged is looking way better than the last version i had and there is a small display bug (see pegged3).





Pitman looks perfect!





Snake looks perfect!






And finally, Vexed looks almost perfect but has also a small display bug (see vexed3).

I haven't tested the SMS version as i'm more concentrated on the SG-1000 at the moment since this console doesn't have many homebrews but thanks to you, now it has! =)
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Post Posted: Fri Mar 19, 2021 7:42 am
Thanks again to both of you Revo and Sly DC.

Finally, another SG-1000 enthusiast :)

I didn't get any hardware mostly because of my excessive confidence in the emulators, and maybe some laziness. I've got an old SMS from 1998 in box at home, so I might pull it out (and see if it works) and buy an Everdrive as you've suggested.

Thanks for the Photos, they make a big difference.

Added fixes:

- Clear the sprite table to 208 on startup. Hopefully that'll remove the errant sprites.
- Fixed the borders (was looking at the wrong tile position)

And um, yeah. The king was meant to look that way :)
Under4MhzPack-1.02.zip (456.64 KB)

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Post Posted: Fri Mar 19, 2021 11:48 am
under4mhz wrote
I didn't get any hardware mostly because of my excessive confidence in the emulators, and maybe some laziness. I've got an old SMS from 1998 in box at home, so I might pull it out (and see if it works) and buy an Everdrive as you've suggested.

Your confidence in emulators is justified. I just tried all versions of all your games on hardware and compared them to Emulicious.
Everything you can see in the screenshots and what is described by Revo, is also present in Emulicious.
The point is that Revo's "real hardware" is underspecified. It does not mention which machine was used, nor which flashcart.
For example the "garbage screen" when loading the sg games and the additional cursors sprites on screen are caused by the state of VRAM left by the Everdrive. You get exactly the same when emulating the Everdrive with Emulicious.
The only issue that I cannot even reproduce on hardware is "bugged" SFX described by Revo when dying in Arno Dash 2.
Maybe he can detail a bit more how to reproduce this because I just killed myself with blocks to test this.

So you could go back to your versions 1.00 and start fixing them while emulating the Everdrive as well.
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Post Posted: Fri Mar 19, 2021 12:45 pm
Calindro wrote
Your confidence in emulators is justified.


Well, no. There are plenty of emulators that aren't close enough to hardware. Emulicious is likely the only one I trust to really show you what you will get on hardware - but even that one might still contain bugs, so I think you should try on hardware from time to time during development and once more before release.

My two cents, of course.
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Post Posted: Sat Mar 20, 2021 1:04 am
Thanks for that Calindro. I've seen the Everdrive option there, but I didn't understand why it was there. Now I know.

Emulicious is a fantastic product and I've been using it consistently for all my game development for two years.
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Post Posted: Sat Mar 20, 2021 10:33 am
As a matter of good practise to avoid any variant of this, you should blank all of RAM, all of VRAM, all CRAM (if you’re not setting it all anyway) and set all the VDP registers on startup. Then you shouldn’t need to test with different BIOSes or loaders.
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Post Posted: Sat Mar 20, 2021 4:03 pm
sverx wrote
Well, no. There are plenty of emulators that aren't close enough to hardware. Emulicious is likely the only one I trust to really show you what you will get on hardware - but even that one might still contain bugs, so I think you should try on hardware from time to time during development and once more before release.

My two cents, of course.


I completely agree with sverx. Emulation will never be 100% accurate compared to a real console. Even MAME still make updates on game consoles, computers, arcade games (a tweak here and there) but it still emulation. At least the software is an exact copy of the original (if dumped correctly of course).

For developing, i do agree that it's easier to do it with emulators (and faster) but to be 100% sure if a game/demo will work, the best is to test it out on a real console. I know this by experience as i helped Daniel Bienvenu test out many of his games (Jeepers Creepers (or aka Happy Holloween), all the BUSTin-Out series and my favorite: "Reversi" which he made for me as i love Othello), and others games i don't remember.

So if any developers wants a good advice, always try out on real hardware as a final test ;)
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