Search found 159 matches
- Mon Mar 10, 2008 12:12 am
- Forum: Demos
- Topic: Japan is back ! Woman at work!
- Replies: 15
- Views: 21815
- Thu Mar 06, 2008 12:52 pm
- Forum: Demos
- Topic: Mini demo / tech MD stuff posted by members :)
- Replies: 94
- Views: 81655
Another thing to be careful about when doing a memory test is to not go outside the areas that get DTACK on a standard MD. Because there is no bus error circuitry, the system will lock up in those areas. Even if your memory modification has DTACK, an unmodified MD will not have the DTACK and will st...
- Fri Feb 29, 2008 1:02 am
- Forum: Demos
- Topic: Mini demo / tech MD stuff posted by members :)
- Replies: 94
- Views: 81655
My method detects 65536B in the emus, instead of 2MB so I assume it's the way to go :D ... but I can't test on my MD because my RAMcart isn't ready... That's because memory mirroring is a hardware effect that doesn't need to be emulated to make games work properly, and therefore is usually not emul...
- Sun Feb 24, 2008 1:26 pm
- Forum: Demos
- Topic: Mini demo / tech MD stuff posted by members :)
- Replies: 94
- Views: 81655
No it's just to detect any extra RAM that anyone might add to the console... I might make use of it for some more complicated features :lol: Then you better check for mirroring. If someone adds a 256K byte RAM, but decodes it into an entire 2 megabyte space, your method will see 2 megabytes. If you...
- Wed Jan 02, 2008 6:22 am
- Forum: Megadrive/Genesis
- Topic: Versions of Sonic 2
- Replies: 7
- Views: 9201
Re: Versions of Sonic 2
I can't believe that guy charges for his emulator, and they aren't even good. Pitty to anyone who actually buys the full version. (It's YM2612 emulation is horrible) The best part is when an emulator of his has had bugs for years, and he still expects you to upgrade to the paid version. (which just...
Looks like a byte swap was missed... but good friggin' lord! I'm not use byte swapping. This is long word reading by byte. EDIT: Hmm... thinking about it a moment, if the above address isn't aligned and you're simulating the alignment error of the 68000, my code above will cause a fault on odd alig...
- Sun Dec 16, 2007 8:39 pm
- Forum: Megadrive/Genesis
- Topic: Genesis Address Bus and Max RAM
- Replies: 35
- Views: 41158
What's the danger of forcing the DTACK signal low (active) when the megadrive drives it high? A big counter is the best solution for Eke's request... As far as I know, DTACK should be connected from open-collector outputs and should never be "driven" high. Basically, what is needed is a bus-error c...
- Sat Oct 20, 2007 4:30 am
- Forum: Megadrive/Genesis
- Topic: Mega Drive dev environment on FreeBSD
- Replies: 4
- Views: 5723
Re: Mega Drive dev environment on FreeBSD
Hello all, Yesterday I was lazy to switch computer to do a little bit of dev on Mega Drive so I start to setup a dev environment on my FreeBSD desktop. I've compiled the FreeBSD port m68k-rtems-gcc and it works fine to produce code for the megadrive (using Stef .ld file from his dev kit), I found a...
- Sat Oct 20, 2007 4:20 am
- Forum: Megadrive/Genesis
- Topic: Compilator warning
- Replies: 12
- Views: 10463
As long as we're all showing off our linker scripts, here's the one I ended up with after getting someone's OS X-based GCC 3.4.4 working. It was a total pain to get initialized global data working. It's not great, but it may have something in it that someone will find useful: SECTIONS { .text 0x0000...
- Fri Oct 19, 2007 1:03 am
- Forum: Megadrive/Genesis
- Topic: Random numbers generation
- Replies: 20
- Views: 17445
Re: Random numbers generation
What source can be used as initial state for pseudo-random generator on SMD (to make generator produce different sequences at each power-up)? Other than not re-initializing the seed after reset, there really isn't any way. The circuitry is the same every time, with esentially no non-determinstic pa...
- Sat Oct 13, 2007 3:44 am
- Forum: Video Display Processor
- Topic: Mega Drive color encoding
- Replies: 17
- Views: 16667
I've researched on PAL-M to NTSC converters and those have prices around $300. Considering that Ebay has offers of Genesis at $10 (buy-it-now) it might be a better option to buy a genesis and switch the circuit board (of course I don't want that giant Genesis logo). Don't try to fight it, just get ...
- Tue Oct 09, 2007 2:14 am
- Forum: Video Display Processor
- Topic: SMS mode on MD/Genesis
- Replies: 15
- Views: 18345
- Sun Oct 07, 2007 5:43 pm
- Forum: Blabla
- Topic: Question...
- Replies: 12
- Views: 11337
- Sun Oct 07, 2007 12:01 am
- Forum: Blabla
- Topic: Question...
- Replies: 12
- Views: 11337
- Sun Sep 30, 2007 1:10 pm
- Forum: Video Display Processor
- Topic: SMS mode on MD/Genesis
- Replies: 15
- Views: 18345
There is a Phantasy Star I cart that works on Megadrive, and it does exactly that. But it still has an SMS bankswitching chip inside. It isn't a generic MD flash cart with an SMS game on it. Also, the Megadrive doesn't have the TMS-9918A video modes of the SMS, so there are a few SMS games that you ...