busy week, but let me post quick update. so, please, do not buy CMedia cards, because at least CMI8738 rev037 (i have) - DDMA doesn't work for me. Maybe, rev033 supports DDMA, but at least one forum member reported has such and let me first make small test tool and we get feedback.
So, currently, I had DDMA running (including on very powerful P4 system with SiS962 chipset motherboard) with "S3 Sound Vibes" sound card and with 4DWave-NX.
So, while S3 card has nothing interesting as features: no Digital Outs, S3FM, fixed wavetable by S3, but at least HW WaveTable - if someone reverse engineer the format, maybe I do it, potentially it can be replaced with something better, build-in S3 DAC. One very positive thing I can say for it is that S3 implementation of DDMA is the first one that I experienced without any weirdness - by "weirdness" I mean it does everything regarding DDMA as I expect from programing point of view. Also, it sound very nice (even S3 DAC is a little noisy) in Impulse Tracker, which I use to test if DDMA is working. I will release "s3ddma" tool soon. Last, but not least in DDMA mode, S3 reports itself as "SB DSP 3.02", which is SBPro card.
Now, 4DWave-NX is simply amazing feature-wise. As someone mentioned in this thread - probably most underrated audio chipset. It has HW SoundFont 2 support (I will definitively work on reverse-engineer it and be able to load 3rd party SF2 banks), external AC97 codec, Digital Output, 26-bit mixer (yes, 26-bit, it's not a typo), Waveblaster header. Basically, only missing thing is FM, but you can use for example Yamaha PCI card for FM and connect it to 4DWave-NX and that way even take use of that 26-bit mixer in 4DWave-NX. That way with 2 PCI cards you have everything and assuming its all DDMA probably close to 100% compatibility.
So, 4DWave-NX conforms to "DDMA Specification 6.0" - I don't know what that means, there is no information I can find about DDMA revisions and it's a little bit different than other DDMA for example S3. there are weirdness, but by that i mean aspects I don't understand. I made DDMA works perfect even not fully understand.
last, but not least, in DDMA mode 4DWave-NX is all-in-one PCI solution, because it can be set to works as "SB DSP 1.01" (SoundBlaster 1), "SB DSP 2.05" (SoundBlaster 2), "SB DSP 3.02" (SoundBlaster Pro) and "SB DPS 4.05", which is SoundBlaster 16. I believe that makes it the only DDMA card that can do SB16.
Again, soon I will release something as "nxddma" tool. Currently, still working on the chipset-side of the DDMA tools. Made VT82C686A working (VT82C686B is working out-of-the-box) and that turned out to be the same fix that makes VT82C596 working. So, that's new information at least to me - indeed VT82C596 has DDMA support.
The Serpent Rider wrote:Intel had only 2 chipsets with DDMA (Intel ones are 430TX and 440BX)
That doesn't make sense. 430TX and 440BX use the same south bridge.
Intel chipsets are the only chipset, where DDMA is spread between North and South Bridge. That's why 440LX doesn't have DDMA support, even its South Bridge is also the same and has DDMA. I hope that makes sense now for you. Also, it's comprehensively documented in Intel datasheets. I will add more on this, when have time, here:
DDMA and PCPCI for Low IQ Individuals (Me included)
So, in short, that's why contrary to others with Intel, when we're talking about DDMA, we're talking about the North, not the South Bridge, because the North Bridge is what determines the DDMA support for Intel chipsets.
Kamerat wrote:gdjacobs wrote:For some reason, Kamerat was able to initialize and use some cards on a vt8233 south bridge with DDMA mode. VIA may not test it, they don't advertise it, but they may not have deleted DDMA functionality from the ASIC, at least in the early V-Link south bridges.
PCI sound cards and Chipsets from various manufacturers...
I might also have been wrong about the ALS4000 running in DDMA mode on the VT8233. According to the datasheet (page 39 and 40) the ALS4000 should support four DMA emulation modes: DDMA, Legacy-DMA read, WB-DMA and "Burst mode for playback". Perhaps somtime I will retest and read out the PCI registers for DMA mode to get things right.
most probably it was in "Legacy-DMA read", because that mode I tested on VT8239A and it's working. Anyway, I will try to make as I said "Swiss-army-knife" set of tools including tool to ask the sound card to tell you the exact mode it's using. besides clear out the situation with CMI8738, which is currently unclear and the audio chips I mentioned above, ALS4000 is my next in line.
Stretch wrote:I compared the memory before and after loading the driver for the CMI8738 in MS-DOS. I am able to get FM playback from a cold boot with no audio driver loaded in autoexec.bat after I poke the mem addresses, but no proper SFX...
at the end I think CMI8738 will be usable only for FM, I kind of doubt even rev033 has DDMA even the cryptic texts of their datasheet i cited here are suggesting otherwise. anyway, let's test on rev033 and then we make final conclusion.