SpritesMind.Net

I'm interested in playing compressed sample by Z80, actually i'm searching the best solution between compression ratio and sound quality. I tried your CVSD example and imo the quality loss is a bit heavy. I guess it works better with 22 khz playback, did you tested it ? I've developped an ADPCM pla...

Nope! CVSD works by comparing the current wave value with a derived sample value. If the wave is larger, it outputs a 1 and adds a delta to the derived sample value; if it's smaller, it outputs a 0 and subtracts a delta from the derived sample value. The key to improving the sound quality is how you...

Okay, following up on the initial post, I've written a Z80 driver to play back CVSD compressed audio. It turns out the Z80 code handles 22050 Hz almost perfectly without waits... which means that with the Z80, that's the maximum frequency for playback. I could make it go slower with a delay after ea...

I know my post on CVSD compression was a bit esoteric for many folks, so I put together a practical example. This uses my new Z80 code discussed in the latest post in that thread to play back music. The main program is the particle fountain example that comes with Steff's Mini-DevKit. I loaded my cv...

As part of my work of Wolf32X, I've been experimenting with various ways to handle the music. One thing would be to simply sample or synthesize the music to raw data, then compress it for storage in the rom. It could then be played back later by decompressing the data on the fly. The trick is to fin...

An exception handler is code the processor jumps to when an error or external event occurs. It usually pushes extra info on the stack that requires a different return opcode than the normal return from subroutine opcode. That opcode for the 68000 is rte, or return from exception. A typical exception...

Remember that the handler set by 0xFFFD08 is an exception handler. You must save and restore any registers you use, and exit using rte. It's also the Main-CPU's responsibility to assert INT02 to the Sub-CPU in its vertical blank handler. bset #0,0xA12000 /* assert sub 68000 INT02 */

I use ReSource for the Amiga to disassemble anything 680x0. It's really a great disassembler. Of course, I run it under UAE these days instead of a real Amiga.

It also saves all registers so you can trash all registers in your V-INT subroutine if you want. Good. One less thing to worry about with the int routine. In any case, it's probably not worth replacing it unless you have a really good reason. Yeah, best to play by the rules unless you have good rea...

If you mean on the Main-CPU side (Genesis), you only want to change the vectors at 0xFFFD00. If you mean the Sub-CPU side (CD), then you want to use the Sub-Processor Int2 entry in the Sub-Processor header table. The Sub-Processor init code starts with a couple headers. .org 0x6000 | Standard MegaCD...

Just some more info on how I use the mouse with the 32X... it should be fairly easy to modify this for use by the Genesis alone if you wanted that. First, I detect the mouse shortly after initializing the Genesis VDP. move.w #0,0xA15128 /* controller 1 */ move.w #0,0xA1512A /* controller 2 */ | look...

You have to give Kaneda enough posts to determine if you're worthy of access.

Uh... now that I think about it, my SEGA Mouse thread should probably be in hardware. Could some with mod powers please move it?

Beta 5 up! Mouse supported is the main feature here.

Looks kinda like my TV when I've got the PAL/NTSC set wrong.

HardWareMan: Have a question for you. Why do you include the font as hex/text instead as a binary? I've seen a few other demos do this too. Is it just habit? If you're used to using C instead for data arrays, you get in the habit of using hex as you don't have binary with most C compilers. I unders...