Search found 62 matches

by andlabs
Tue Nov 16, 2010 8:20 pm
Forum: Sound
Topic: VST using Gens ym2612 emulation
Replies: 40
Views: 14722

superjoebob wrote:Look's cool but unfortunately I don't have a Mac :?. Guess I won't stop working on mine just yet.
It's crossplatform; there are links to other binaries in the thread =P But do as you will; it doesn't hurt to have something that suits your needs.
by andlabs
Tue Nov 16, 2010 11:34 am
Forum: Sound
Topic: VST using Gens ym2612 emulation
Replies: 40
Views: 14722

I didn't want to mention it here until I wrote my own sound driver (I've just started writing it...) but I have been developing a more advanced tracker for the Genesis for my needs. I'll write a more appropriate thread here when I make my sound driver =P
by andlabs
Wed Nov 03, 2010 5:13 pm
Forum: Mega/SegaCD
Topic: Small Sega CD PCM question: sample rates
Replies: 12
Views: 8404

Well I played around with it a bit more, especially with what TascoDLX said about 32khz, and... turns out every sample is tuned to something completely different, meaning I'd have had to try random values from that list within the $0..$7C4 range, though the value for $7C4 (the closest to 32khz forma...
by andlabs
Fri Oct 15, 2010 9:22 pm
Forum: Mega/SegaCD
Topic: Small Sega CD PCM question: sample rates
Replies: 12
Views: 8404

Yes, unfortunately that is too high of a frequency, and the note comes out wrong. Here is the sample after converting to 8-bit unsigned. It should be a bass note.
by andlabs
Thu Oct 14, 2010 11:36 pm
Forum: Mega/SegaCD
Topic: Small Sega CD PCM question: sample rates
Replies: 12
Views: 8404

In that case, let me see if I understand properly: The FD value is split as so: F = FD & 0x7FF; // 2047 MULT = (FD >> 11) & 0x1F; With this, I get base_sample_rate = F * 12500000 / (384 * 2048) and the final sample rate is base_sample_rate * MULT? I just tried it on a bass sample which appears to ha...
by andlabs
Mon Oct 11, 2010 7:30 pm
Forum: Mega/SegaCD
Topic: Small Sega CD PCM question: sample rates
Replies: 12
Views: 8404

Sorry for the delayed response, but I'm getting confused by some of the posts. I understand what TascoDLX means, and in fact I can use that knowledge later, however I'm still not understanding what's happening when the FD goes above 2048 — I still have to sample at 32Khz and resample it myself later...
by andlabs
Mon Aug 30, 2010 5:37 pm
Forum: Mega/SegaCD
Topic: Small Sega CD PCM question: sample rates
Replies: 12
Views: 8404

Okay, sorry for the double post but does this formula hold for higher values of the FD register? I have a sample which is usually played around the area where C would be FDH = $42 and FDL = $06 and I'm getting 268650 hz with that, which is outrageously high even for current hardware(?), and wrong wh...
by andlabs
Sat Aug 28, 2010 3:57 am
Forum: Mega/SegaCD
Topic: Small Sega CD PCM question: sample rates
Replies: 12
Views: 8404

Thanks, that was exactly it — Rex Sabio's handwritten formula had meaning after all =P

For the record the value for my FDH/FDL was 16609.8276774089 hz — the sampling rate of most of the PCM samples in Sonic CD.
by andlabs
Fri Aug 27, 2010 7:40 pm
Forum: Mega/SegaCD
Topic: Small Sega CD PCM question: sample rates
Replies: 12
Views: 8404

Small Sega CD PCM question: sample rates

Hi. I'm just wondering how the Sega CD PCM chip's FDH/FDL registers correspond to sample rates, namely if FDH==4 and FDL==$15 (hex). I understand what the chip is doing (similar to a rudimentary out[x]=in[x*inrate/outrate] resampler) but I don't understand how to convert the resultant increment back...
by andlabs
Tue Aug 24, 2010 5:49 am
Forum: Megadrive/Genesis
Topic: i wanna know how to convert bin to asm.
Replies: 8
Views: 4532

The issue with disassembling is that even in its current state IDA isn't smart and, for example, wrongly sees palettes as offsets and turns them into labels, doesn't follow pc-relative jumps with index, etc. I've done a heckuva lot of disassembling with IDA (again, primarily to get the DAC samples o...
by andlabs
Sun May 02, 2010 6:26 am
Forum: Sound
Topic: Rocket Knight digital sounds
Replies: 9
Views: 4608

Here are the SF2SCE samples ripped out of the game (you can use these to compare). Output sample quality depends not only on the sample playback code (as Tiido says) but also on other code as well: The Genesis docs say to stop the Z80 each controller read You will need to stop the Z80 to read/write...
by andlabs
Fri Apr 30, 2010 9:47 pm
Forum: Sound
Topic: Rocket Knight digital sounds
Replies: 9
Views: 4608

I have been disassembling and researching RKA's sound driver (my laptop is back from the shop so I can continue working on it). There is code for DAC support, but I don't think it is used. One thing the driver does for FM voices is that it has a copy of the voice bank for each Z80 bank, however I'm ...
by andlabs
Thu Mar 18, 2010 10:51 pm
Forum: Megadrive/Genesis
Topic: Official Sega Documentation, More is required?
Replies: 11
Views: 4968

First off, I'm not sure if "programming documents" would include source code. With that... I suspect it's not really worth it. The development docs for the Sega CD and 32X got leaked quite a while ago and the Megadrive/Genesis is a pretty well understood beast these days. The kinds of details that a...
by andlabs
Sat Jan 16, 2010 5:13 pm
Forum: Super 32X
Topic: SH-2 question(s)
Replies: 2
Views: 2954

Thanks! Does that also explain why the disassembler disassembles an instruction after the ret? And would I have to code like that myself?
by andlabs
Wed Jan 13, 2010 11:02 pm
Forum: Super 32X
Topic: SH-2 question(s)
Replies: 2
Views: 2954

SH-2 question(s)

Hi. I'm disassembling some 32X code primarily for my own research purposes and I was wondering if you could help me with something I can't decipher, and the SH-2 docs don't help with this case: mov #0,r0 mov.w loc_whatever, r1 braf r1 ; consider this at address 0x6789ABC) ; ... loc_whatever: .data.w...