Search found 2776 matches

by Stef
Sun Feb 04, 2007 10:42 pm
Forum: Super 32X
Topic: FIFO
Replies: 10
Views: 6655

Re: FIFO

Hi you all. Still on 32x dev' ;) I'm looking at the FIFO. First of all, is it usable ? Or is it DREQ only ? The 68k writes to A1 5112h, and the SH2s read 2000 4012h. But is it a stack, a heap or anything ? And if so, how big is it ? I mean, if the 68k want to put several datas, does it have to wait...
by Stef
Sat Feb 03, 2007 8:59 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

For now i'm doing (byte + byte) and i don't check for carry. The normal way is just (byte + byte) then limit result if carry happen. Using / 2 will limit your maximum volume for each channel, that give too quiet sound. I'm also mixing dummy bytes but i bypass some others part as address increment......
by Stef
Sat Feb 03, 2007 11:46 am
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

Actually my code just handle 2 samples at 11 Khz (and not 8 Khz as i first though) =) but i've to do some changes since when only 1 sample is played, it's played at 14 Khz (i've to add a wait loop somewhere).
by Stef
Fri Feb 02, 2007 2:35 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

Yep 2 channels isn't bad after all.
But i had a quick look on genesis games (Thanks again Kaneda :p), it appears that beats and/or drums often need a high rate, i saw some 22 Khz rate used here and there... it would be very difficult to maintain 22 Khz with 2 samples played at the same time !
by Stef
Fri Feb 02, 2007 1:58 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

Is your modded KMod available ? That new feature is really useful. well, it's a hybrid version badly coded from 0.6_beta you could download it from http://www.spritesmind.net/share/gens_DACFreq.zip look at where the DAC value was written, it's now the frequency (so you loose the DAC value..) I'll d...
by Stef
Fri Feb 02, 2007 1:18 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

Why do you need to access YM2612 with 68K and z80 at the same time ? Because i'm using the Z80 to play sample and i don't want to interrupt it to keep a good playback quality. We can use the 68000 to handle MIDI YM2612 playing and the Z80 for DAC playing but if we need to halt the Z80 during 68000 ...
by Stef
Fri Feb 02, 2007 12:26 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

FXaddr++ ? are you coding the Z80 in C ? that explain some stuff :)
Maybe your Z80 C compiler isn't a good optimiser...

Just something about the YM2612 : have you to stop the Z80 to access it from the 68000 cpu ? from what i saw, we can access it from A04000 only so we need the Z80 bus... too bad :-/
by Stef
Fri Feb 02, 2007 10:24 am
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

KanedaFr wrote:ok, i modded KMod
I was able to spy the DAC freq update....
hehe, neat feature ;)
Anyway playing something > 16 Khz is just a waste :p
I would love to have a z80 code capable of mixing 2 channel at 16 Khz. For now i've 2 channels at 10 Khz...
by Stef
Fri Feb 02, 2007 8:58 am
Forum: Tools
Topic: ROM Header and Emulators
Replies: 9
Views: 5068

They do work but they contains additionnal hardware...
by Stef
Thu Feb 01, 2007 7:24 pm
Forum: Tools
Topic: ROM Header and Emulators
Replies: 9
Views: 5068

Unlicensed... it's the word.
by Stef
Thu Feb 01, 2007 1:43 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

Not true for my system !!! I've modified the audio mixing part and now it has really great sound output, with almost 100% stereo separation. Original sound output system has poor stereo (50% separation) and a bit distorted (very very slightly). You modified the audio output :p without modification,...
by Stef
Thu Feb 01, 2007 1:15 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

Well, i just did my first Z80 asm programming these last days and i've to admit i don't like it much... Z80 instruction set isn't the best one :-/ no flag modification for 16 bits arithmetic, 8 bits arithmetic only on register A, no test or tst instruction... My first program was a 4 bits PCM player...
by Stef
Thu Feb 01, 2007 7:43 am
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

I have to disagree, the genesis DAC sounds a bit woofed. Yesterday i did some test of my Z80 wav player (16 Khz sample) and the sound of the genesis was not as good than on emulator imo. For good quality sample, the genesis generally sound not as good than emulator (PC sound card has better output) ...
by Stef
Wed Jan 31, 2007 2:26 pm
Forum: Sound
Topic: how can i do music on megadrive?
Replies: 288
Views: 138280

I re-tried on Kega, it's true the sample of Duke Nuken sounds good. I'm really impressed for 5 Khz sample !
by Stef
Wed Jan 31, 2007 2:18 pm
Forum: Tools
Topic: Easy68K?
Replies: 21
Views: 10928

It's surprising to see a basic compiler as fast than C compiler... anyway, why not ? But the main problem of basic language is the "non portability". You can find a C compiler for almost all target CPU which is not the base with basic.