Search found 2982 matches

by Stef
Tue Dec 19, 2006 1:42 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 230409

Re: how can i do music on megadrive?

I'm pretty sure the, Z80 won't have the guts for a mod player, specialy that you'll have to mix in software all channels (and mixing is a killer) Actually I think it is possible on z80, as in Duke3D there are 4 channels mixed together.... @ 5KHz 4 channels at 5 Khz :p I didn't known the sound engin...
by Stef
Tue Dec 19, 2006 1:29 pm
Forum: Sound
Topic: I made a discovery...
Replies: 32
Views: 11334

Your information is quite usefull :) As i never found any informations about the YM2612 busy flag and hardware latency, i never bothered with that... this absolutly don't change anything for game emulation has none trying to send 96 Khz samples X'D I think the latency can change depending the regist...
by Stef
Tue Dec 19, 2006 7:56 am
Forum: Video Display Processor
Topic: Is DMA useful ?
Replies: 30
Views: 12856

It's the advantage of having the possibility to test it out ;)
On Gens it should report a better frame rate, because of the no VRAM latency stuff.
by Stef
Mon Dec 18, 2006 2:49 pm
Forum: Megadrive/Genesis
Topic: Sega2.doc is enough, Really?
Replies: 23
Views: 11106

ob1 wrote:In his Sega Genesis VDP Documentation, Charles MacDonald says
"The name table size cannot exceed 8192 bytes, so while a 64x64 or 128x32 name table
is allowed, a size of 128x128 or 64x128 is invalid."
Yep that's true, but i wanted to keep it simple :p
by Stef
Mon Dec 18, 2006 2:46 pm
Forum: Video Display Processor
Topic: Is DMA useful ?
Replies: 30
Views: 12856

If you want to test only some CPU related stuff Gens is instead more accurate... I do my testing on the real hardware now, I specially built a SRAM cartridge for such purpose (pics on my site). 256KB of unlimited rewrites, programs in 5 secs, 3 in pure DOS. Program with my MPCP (damn, off topic). I...
by Stef
Mon Dec 18, 2006 1:42 pm
Forum: Video Display Processor
Topic: Is DMA useful ?
Replies: 30
Views: 12856

I did my 512 and 960 color test without DMA. Results are good on emu but suck on real thing. Maybe DMA helps... source for 960 color demo available on request. That always interets me :) I think we should have a section to post member's creations in the forum :) One important thing to know : Kega F...
by Stef
Mon Dec 18, 2006 8:43 am
Forum: Megadrive/Genesis
Topic: Sega2.doc is enough, Really?
Replies: 23
Views: 11106

You have to know the base hardware limitation and more specifically the VDP limitations : - The VDP draw image from TILE and TILEMAP. - A TILE is 8x8 pixels sized box and 4 BPP so you can define it by 8x8x4 = 256 bits = 32 bytes. - The tilemap defines the screen image. It can be sized from 32x32 to ...
by Stef
Sun Dec 17, 2006 8:58 pm
Forum: Megadrive/Genesis
Topic: about compile error
Replies: 10
Views: 4856

Unfortunatly the library isn't compatible, each demo are specific to the lib and "dev kit" used :-/
I should do more demo for this mini dev kit.
You can also have a look on the different headers, they help a lot :)
by Stef
Sun Dec 17, 2006 8:48 pm
Forum: Megadrive/Genesis
Topic: Genny and 3D
Replies: 138
Views: 38356

In Silpheed only your ship and ennemy ships are really calculated and draw. The background 3D is just a "movie", all is read from the CD in real time. That definitly not "real time 3D" but a soft of precalculated 3D (i guess the compression format is adapted to the flat rendering). The segaCD vector...
by Stef
Sun Dec 17, 2006 1:07 am
Forum: Megadrive/Genesis
Topic: about compile error
Replies: 10
Views: 4856

Welcome on the board :) First, i don't know where you got that make.exe file, but a makefile by borland doesn't sound good... I don't really want to "sell" it but you should try that mini devkit for genesis : http://www.spritesmind.net/_GenDev/forum/viewtopic.php?t=14 It only includes the strict min...
by Stef
Fri Dec 15, 2006 7:26 am
Forum: Tools
Topic: Gens KMod & $E00000-$FE0000?
Replies: 4
Views: 3794

$E00000-$FEFFFF as VRAM ??

This area is recognized as main ram in Gens and i think it's the same for Gens KMod.
by Stef
Wed Dec 13, 2006 10:33 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 230409

it doesn't have "self feedback" for the first slot. As far as I know (and tested), OPL2/OPL3 have 8 levels of feedback on their operators. Self feedback ? anyway i wasn't sure about this one, i though it was a OPN/OPM specific feature ;) Edit : I just checked and you're totally right :) The YM2612 ...
by Stef
Wed Dec 13, 2006 9:20 am
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 230409

Learning Z80 assembly and how YM2612 and PSG works. Try getting an old soundcard with OPL3 FM synthesizer and try programming it, YM2612 and OPL3 are programmed in similiar ways. Here's a guide to OPL3: http://www.gamedev.net/reference/articles/article447.asp How close is standard Adlib to the YM26...
by Stef
Sat Dec 09, 2006 1:56 pm
Forum: Cartridge
Topic: Problem with accessing SRAM
Replies: 10
Views: 5607

Yeah, the IO reg acts on some ROM port pin's so the cart has to wired them somewhere... Almost emulator expect the SRAM to be located at 0x200000. The SRAM location in rom header is sometime wrong and emulator can't rely only on that. Anyway i believe Gens does use it so it should work in our case.
by Stef
Fri Dec 08, 2006 10:25 pm
Forum: Cartridge
Topic: Problem with accessing SRAM
Replies: 10
Views: 5607

Strange.. are you doing byte access to the IO reg port ? then are you waiting some cycles (doing 6 or 7 nop) before doing your write and your read ? the hardware takes sometime to "acknowledge" your command.