VOGONS


First post, by CkRtech

User metadata
Rank Oldbie
Rank
Oldbie

So I found a Sound Blaster 32 (CT3600) at a recycle place for just under $2. I picked it up, brought it home, and tried it in a test bench I am currently using (Asus SP97-V with Pentium 200 MMX). Didn't really get far with it as the speaker/headphone port had one cap that was blown (right channel out on amplifier) as well as a generally loose 1/8" jack. I replaced both the output caps on the amp as well as the output jack. This restored the right channel and provided better headphone connection, however there are a few other issues.

Windows 95 booting to DOS prompt -

1: For whatever version of Diagnose that I am use post-CTCU and CTCM, 8 bit testing works fine... but 16 bit testing plays back with LOUD - we are talking LOUD - static/noise over it. A220 I5 D1 H5. If I reconfigure the card to use DMA 1 instead of DMA 5 for the high channel, it is mostly cleaned up but still has a bit of static ever so briefly. So I seem to have definite issue with High DMA - but also a minor issue with low DMA during 16 bit playback.

Duke 3D plays all sounds under that same loud garbage. Changing the setup to be 8 bit cleans it right up. Leaving the other settings - 8 voices, 44 Khz, etc is fine.

2: AWEUTIL seems agreeable - at least for initialization and reverb/chorus changes. A newer version of it (with fewer options) just turns on deafening noise.

3: Adlib-sound works after using the earlier version of AWEUTIL to initialize.

4: WavEffects testing worked once for maybe 5 seconds - playing that little jam tune - and then dropped out leaving only soft volume, spacey sound fx behind. It was as if the instruments just decided to quit. All consecutive attempts since that point produce those weird sounds.

Games like DOOM, Wolfenstein 3-D, Epic Pinball, Jazz Jackrabbit, Commander Keen 4, etc, are fine.

I have been googling around a bit (and some of the results return me to a vogons thread), and I am uncertain as to what problem or problems I have. Some newsgroups mentioned the exact symptoms circa 1996 without a definitive solution.

No resource conflicts are noted from CTCU in DOS or in Windows 95 (after attempting to use Windows 95 to install/initialize the drivers) Windows 95 complains about a synth sbk file error load upon loading the OS. I have no RAM installed on the card.

Displaced Gamers (YouTube) - DOS Gaming Aspect Ratio - 320x200 || The History of 240p || Dithering on the Sega Genesis with Composite Video

Reply 1 of 10, by CkRtech

User metadata
Rank Oldbie
Rank
Oldbie

Well, I grabbed another motherboard out of my box and booted to the exact same layout of components - no problems at all.

So I assume the issue is possibly with either voltages (maybe some bad caps. No visible bulging, but you never can tell), bus speed, or a bizarre compatibility issue.

Wouldn't mind resolving the issue with the other board because SCIENCE, but I think I will consider the repair complete.

Displaced Gamers (YouTube) - DOS Gaming Aspect Ratio - 320x200 || The History of 240p || Dithering on the Sega Genesis with Composite Video

Reply 2 of 10, by Jo22

User metadata
Rank l33t++
Rank
l33t++

It's a Vibra16S, right ? The 2502 chip belongs to that series..
A few years ago I heard that some Vibras do use fake 16Bit DMA.

Besides, you card has no on-board memory, so it is highly recommend
to add a bit of SIMM memory, so the EMU8000 can work properly..

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 3 of 10, by gerwin

User metadata
Rank l33t
Rank
l33t

The CT3600 card contains the CT2502 Vibra chip. But it is not Vibra16S, only the CT2504 chip is called Vibra16S.

The bad behaviour in the first post is not normal for such a card.

--> ISA Soundcard Overview // Doom MBF 2.04 // SetMul

Reply 4 of 10, by Jo22

User metadata
Rank l33t++
Rank
l33t++

Ah okay. I didn't notice that this was abnormal behaviour for a PnP card from Creative.

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 5 of 10, by gerwin

User metadata
Rank l33t
Rank
l33t

I mean, I used a SB16 CT2940 with a CT2502 Vibra Chip for a while. So that is the same as in the first post but without the AWE midi synth. Compatibility with about 50 nineties DOS games was fine. Don't recall any sudden issues where it started to output static noise when configured as SB16.

Suppose AWUTIL is needed to enable adlib an any card with AWE synth, because the Adlib output signal goes through the AWE's DAC, IIRC.

--> ISA Soundcard Overview // Doom MBF 2.04 // SetMul

Reply 6 of 10, by Jo22

User metadata
Rank l33t++
Rank
l33t++

Wasn't there once a discussion about how Vibras used two 8Bit DMA transfers to fake a 16Bit DMA ?
It's been long ago, but I believe not all Virbras were affected by this. Anyway, that's all I do remember.

I haven't much used PnP cards, since I had bad experience with them. My most vivid memory was that IRQs changend for no reason during bootup.
Sometimes the high DMA was on 5, then on 7, then somewhere else. For me, this was too much of it and I drew a line.
No more PnP cards from Creative. Well, almost. The CT1920 is okey dokey I guess. 😊

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 7 of 10, by firage

User metadata
Rank Oldbie
Rank
Oldbie

The only such reference I see is referring to the late Vibra 16 XV, and it's immediately contrasted with the Vibra16S which is fine in that regard. It's pretty obvious looking at the card it was used on, the CT4170, as the 16-bit half of the ISA edge is bare.

My big-red-switch 486

Reply 8 of 10, by Jo22

User metadata
Rank l33t++
Rank
l33t++

You meant this thread ? Yes, it could have been this one, but it doesn't look farmiliar to me.
Anyway, as I already said, I gave up on PnP Cards from Creative long ago.
After I sold my PnP collection, I felt much better.

If you're looking for more Information, please have a look at Great Hierophant's blog.
It's fun to read an has a lot of valuable Information.

http://nerdlypleasures.blogspot.de/2012/07/so … ibulations.html

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 9 of 10, by firage

User metadata
Rank Oldbie
Rank
Oldbie

There's a ton of interesting information about the Vibra chipsets and the SB16/AWE series in general in this old post: https://web.archive.org/web/20140906114713/ht … 6.html#msg23496
It's not all 100% accurate, such as the claim that the CT1747 chip incorporated CQM instead of an OPL3 core. He's mixing up the CT1978 with the CT1747 when talking about CQM and OPL there.

My big-red-switch 486

Reply 10 of 10, by Jo22

User metadata
Rank l33t++
Rank
l33t++

Looks good! Thanks for sharing! 😀

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//