Just to clarify: by internal speaker you mean the thing that only makes beeps (commonly referred as PC Speaker)?

If that's the source of the noise then changing your soundcard probably isn't going to fix it because that speaker is wired up to the 5v rail on your motherboard. These beeps are not produced by the soundcard.

If the noise is coming through external speakers (from the souncard's rear OUT) then it might be a Soundcard issue. If your motherboard has a PCI or ISA slot riser then it's an easy thing to test. ISA is best for DOS.

It can also be bad components on the motherboard. Since your soundcard is integrated it can pick up interference.

Thanks for the reply!

Hezus wrote on 2023-01-08, 21:58:

Just to clarify: by internal speaker you mean the thing that only makes beeps (commonly referred as PC Speaker)?

Actually no, it's not a traditional PC speaker as in BIOS beep type buzzer (there's one of those separately). It's an actual audio speaker that has an internal connection to the integrated sound card audio out. You can see it in right edge of the photos of the internals - it's pretty substantial and doesn't sound too bad at all, even though it's obviously only mono. (Apart from the interference, that's also there on external speakers)

Pretty unusual, I think? I can't imagine many, if any, standalone sound cards would have an internal connection for this?

I have been playing around with some DOS games, but I guess the ones I actually remember nostalgically were the very last generation of DOS game - things like Caesar 2 and C&C Red Alert etc. Would they work with something like a PCI SB128 ? Or any thoughts on whether a late ISA card like SB AWE64 still be likely to help avoid the "thinking noise"?

It's interesting that although you have a PIII 500 Katmai, it's only fitted with a passive cooler. I only have a 50 MHz faster CPU (550) and it was fitted with a small noisy fan powered from the mainboard. Passive-cooled I have a PII 350 Deschutes, where the mainboard does not have a connector for cpu fan.
In addition to the 2 mainboard versions, these machines also had 2 PSU types - 90W and 120W - what version do you have?
The internal speaker automatically disconnects when detecting the connection of the AUDIO OUT jack on the back and I don't personally see any disturbing sound on my piece (CPU fan I have replaced).
If you will install a different audio card, it is necessary to turn off the existing onboard in the BIOS (device security option).
Mine works without problems with Coppermine Celeron 900 (via slotket) and Voodoo3 2k, TNT2 M64 (and Radeon 7200 PCI - but here 90W PSU discourages me from using it permanently).

For more tips and experience with tweaking Deskpro EN SFF I can recommend a page of one of the members here: http://kentie.net/article/retropc/index.htm#throttle

I use the same system for retro gaming, though upgraded with a Tualatin CPU (running at 100MHz FSB). I don't remember how noisy the built in card was. I recommend a standalone ISA card; ESS, Aztech, MK8330. It's a broad topic. A separate sound card also gives you a game port for midi purposes. Unfortunately on my machine the built in speaker refuses to produce any sound. Although you mention a separate speaker, as far as I know the big speaker is also uses for PC speaker audio.

Mine came with a 550 CPU and no fan, I think the cooler above must have been modified.

Oetker wrote on 2023-01-09, 10:14:

Mine came with a 550 CPU and no fan, I think the cooler above must have been modified.

I doubt that, because the two boards differ apart from the minor details just in the presence of the CPU fan connector. Also, fan screws are typical "compaq" with grooves for a flat screwdriver or TORX wrench. The cable is very short just enough to reach the connector.

I used to have a number of these SFF's. As you say of course your very limited on upgrade options been very proprietary but being a SFF you have to expect that.
Never experienced the thinking noise however this was 10+ years ago when components were younger and closer to being on spec.

If you have any PCI sound card you could try that just to see if it resolves the issue.
For PCI soundcard options with dos support the PCI128 will work if you already have one, however a SBLive, Audigy, Audigy 2 will offer the exact same dos compatibility but EAX sound for windows games for not much more money. You also have Aural Vortex 1 and 2 (the 2 supporting A3D 2.0 in windows) or Yamaha YMF cards to name the popular choices that are common.

If you have an ISA slot ISA cards will always give the least trouble in dos games however are a bit more hiss and crackly compared to PCI card so both are a compromise, you just have to decide if your going to spend more time in windows or dos, or you can always install both and ISA and PCI card.

Many thanks for all of these very helpful comments! The "kentie" article was very interesting too.

Looking in more detail, it looks like I have the older revision of the motherboard PCB, and just a 90w PSU. I was mistaken on thinking there was also a buzzer - will the internal speaker still work as a "pc speaker" if a standalone sound card is fitted?

I don't have any sound cards at all at yet, so I'd be buying from (UK) eBay. It does look like the PCI cards are less than half the price of ISA, which is tempting if I can rely on at least basic DOS comparability. I think in all honesty I'll be spending more time in Windows, but wouldn't want to give up occasional DOS games altogether...

There seem to be plenty of SB128, Live!, and Audigy cards for around £15. Each of these seems to have loads of different PCB designs and model numbers though. Is there anything to choose between them?

One other thing is I've noticed the CD-ROM cable is quite damaged. Where it's been folded over as part of the velcro cable management it's worn through enough to see bare metal, and the drive end cable clip is snapped on one side. I was expecting it to be 44-pin, but it actually seems to be 50-pin! That seems really unusual - any tips on what to search for to find a replacement? There seem to be a handful of ribbon cables on eBay described as 50-pin, including some described as SCSI, but it's hard to tell if the spacing is right ...

I have one of these in excellent working order if you're interested in a spare. Pretty sure it's the same 500mhz version you have. I have the same 90w power supply but my CPu frequency jumpers have markings up to 700mhz.

justin1985 wrote on 2023-01-09, 23:18:

There seem to be plenty of SB128, Live!, and Audigy cards for around £15. Each of these seems to have loads of different PCB designs and model numbers though. Is there anything to choose between them?

SB128 is a basic card which has no EAX, Unless you get one for free I wouldn't waste my time/money

SBLive!
CT1024, CT4760, SB0060 SB0220 are all ok
Avoid SB0200/0203 and SB0410

Audigy cards SB0570, SB0310, are software based, so would avoid unless free
The Audigy cards you do want are SB0160, SB0090

I've just pulled all these quickly from wiki where you can get more details on the difference between cards
https://en.wikipedia.org/wiki/Sound_Blaster_Audigy

I agree if its mainly windows games I'd start out with one of these cards and work out if you really need a isa card or not.

chinny22 wrote on 2023-01-10, 14:00:

SB128 is a basic card which has no EAX, Unless you get one for free I wouldn't waste my time/money

Technically, the SB128 does support EAX, but it's done in software, unlike the SBLive/Audigy cards which support it in hardware.

In practice, this means that EAX games won't sound as good on the SB128, and that the CPU utilization will be much higher in such games with that card.

justin1985 wrote on 2023-01-09, 23:18:

One other thing is I've noticed the CD-ROM cable is quite damaged. Where it's been folded over as part of the velcro cable management it's worn through enough to see bare metal, and the drive end cable clip is snapped on one side. I was expecting it to be 44-pin, but it actually seems to be 50-pin! That seems really unusual - any tips on what to search for to find a replacement? There seem to be a handful of ribbon cables on eBay described as 50-pin, including some described as SCSI, but it's hard to tell if the spacing is right ...

The cable to the CD drive is therefore 50 pin, as it not only transmits audio and data signal, but also provides power to the drive. There's no other power cable going into the drive.

justin1985 wrote on 2023-01-09, 23:18:

I was mistaken on thinking there was also a buzzer - will the internal speaker still work as a "pc speaker" if a standalone sound card is fitted?

I have no idea, maybe it works like a beeper (i.e. beeps on boot and errors) - if you add a separate soundcard to the system, you should connect it with a cable to the motherboard (J11 connector between IDE and FDD ports).

keenerb wrote on 2023-01-10, 00:28:

I have one of these in excellent working order if you're interested in a spare. Pretty sure it's the same 500mhz version you have. I have the same 90w power supply but my CPu frequency jumpers have markings up to 700mhz.

Thanks for the offer - but I really don't have space to start collecting spare machines ...

chinny22 wrote on 2023-01-10, 14:00:

SB128 is a basic card which has no EAX, Unless you get one for free I wouldn't waste my time/money SBLive! CT1024, CT4760, SB00 […]
Show full quote

SB128 is a basic card which has no EAX, Unless you get one for free I wouldn't waste my time/money
SBLive!
CT1024, CT4760, SB0060 SB0220 are all ok
Avoid SB0200/0203 and SB0410
Audigy cards SB0570, SB0310, are software based, so would avoid unless free
The Audigy cards you do want are SB0160, SB0090
I've just pulled all these quickly from wiki where you can get more details on the difference between cards
https://en.wikipedia.org/wiki/Sound_Blaster_Audigy
I agree if its mainly windows games I'd start out with one of these cards and work out if you really need a isa card or not.

I had no idea there was so much variation between the cards within each line - that is really helpful - thank you!

It looks like an another significant difference, or at least pattern, is the SB Live! cards seem to have a game/MIDI port, but the Audigy cards don't, by the look of it? I'll see if I can get hold of an SB Live at a reasonable price and shipping ...

Ydee wrote on 2023-01-10, 16:02:

The cable to the CD drive is therefore 50 pin, as it not only transmits audio and data signal, but also provides power to the drive. There's no other power cable going into the drive.

Any ideas of what to search for in order to find a replacement for this cable? It LOOKS like all of the 50-pin ribbon cables I can find on eBay UK are SCSI cables, which seem to have a 2.54mm pin pitch, the same as a normal IDE cable. The Compaq CD cable is much denser (looking like a 44-pin laptop style IDE, just wider). On the motherboard photos above, you can see the 50 pin connector is actually narrower than the 40 pin ones. So I figure it must be 1.27mm pitch, like laptop 44-pin IDE?

The closest I've found is this at Mouser: https://www.mouser.co.uk/ProductDetail/Harwin … 7JwUBPYLg%3D%3D
Equivalent product spec for a different brand, set out in a helpful format here: https://www.mouser.co.uk/datasheet/2/527/ffsd-2854094.pdf - so basically 1.27mm pitch, double row x 25 position, female to female.

Which seems insanely expensive at £33 for a 30cm cable! RS have a similar one slightly cheaper at £21 https://uk.rs-online.com/web/p/ribbon-cable/9011790 - but that still seems very expensive for a cable! Rapid and other UK go-to electronic component suppliers seem to sell only reels of the cable at proportionate prices, no connectors.

Does anyone know if there any other way this cable might be described which might help me find one (second hand?) at a more reasonable price?

Otherwise I'd just be tempted to wrap the damaged wire insulation sections with Kapton tape, and repair the snapped connector clip with glue (Would PlasticWeld work on the kind of plastic used? or would it have to be epoxy?). It does actually still work, just seems not ideal to leave it in this condition / in need of restoration.

justin1985 wrote on 2023-01-10, 21:33:

It looks like an another significant difference, or at least pattern, is the SB Live! cards seem to have a game/MIDI port, but the Audigy cards don't, by the look of it?

They do, but it comes on a separate bracket and connects to the Audigy via ribbon cable.

justin1985 wrote on 2023-01-11, 13:42:

Any ideas of what to search for in order to find a replacement for this cable? It LOOKS like all of the 50-pin ribbon cables I c […]
Show full quote

Ydee wrote on 2023-01-10, 16:02:

The cable to the CD drive is therefore 50 pin, as it not only transmits audio and data signal, but also provides power to the drive. There's no other power cable going into the drive.

Any ideas of what to search for in order to find a replacement for this cable? It LOOKS like all of the 50-pin ribbon cables I can find on eBay UK are SCSI cables, which seem to have a 2.54mm pin pitch, the same as a normal IDE cable. The Compaq CD cable is much denser (looking like a 44-pin laptop style IDE, just wider). On the motherboard photos above, you can see the 50 pin connector is actually narrower than the 40 pin ones. So I figure it must be 1.27mm pitch, like laptop 44-pin IDE?

The closest I've found is this at Mouser: https://www.mouser.co.uk/ProductDetail/Harwin … 7JwUBPYLg%3D%3D
Equivalent product spec for a different brand, set out in a helpful format here: https://www.mouser.co.uk/datasheet/2/527/ffsd-2854094.pdf - so basically 1.27mm pitch, double row x 25 position, female to female.

Which seems insanely expensive at £33 for a 30cm cable! RS have a similar one slightly cheaper at £21 https://uk.rs-online.com/web/p/ribbon-cable/9011790 - but that still seems very expensive for a cable! Rapid and other UK go-to electronic component suppliers seem to sell only reels of the cable at proportionate prices, no connectors.

Does anyone know if there any other way this cable might be described which might help me find one (second hand?) at a more reasonable price?

Otherwise I'd just be tempted to wrap the damaged wire insulation sections with Kapton tape, and repair the snapped connector clip with glue (Would PlasticWeld work on the kind of plastic used? or would it have to be epoxy?). It does actually still work, just seems not ideal to leave it in this condition / in need of restoration.

The correct part number is 314014-001 (should be printed on the cable)...usually described something like "Compaq / HP CD-ROM cable (IDE)". Think I have a spare somewhere - if you're still looking, and I find it, you can have it no charge 😀

PC Hoarder Patrol wrote on 2023-01-12, 01:56:

The correct part number is 314014-001 (should be printed on the cable)...usually described something like "Compaq / HP CD-ROM cable (IDE)". Think I have a spare somewhere - if you're still looking, and I find it, you can have it no charge 😀

That would be absolute amazing - incredibly kind of you! Obviously I'd be happy to PayPal to cover costs, at the least.

How can I contact you? It doesn't look like I'm allowed to use DMs on here yet 🙁

justin1985 wrote on 2023-01-14, 12:36:

PC Hoarder Patrol wrote on 2023-01-12, 01:56:

The correct part number is 314014-001 (should be printed on the cable)...usually described something like "Compaq / HP CD-ROM cable (IDE)". Think I have a spare somewhere - if you're still looking, and I find it, you can have it no charge 😀

That would be absolute amazing - incredibly kind of you! Obviously I'd be happy to PayPal to cover costs, at the least.

How can I contact you? It doesn't look like I'm allowed to use DMs on here yet 🙁

Finally found the little beggar! 😀 ...it's the original cable from my own (currently busted) Deskpro SFF P3 450 - I replaced the original working CD-ROM drive and the new one came complete with cable.

Think I can still DM you, and you can read it but can't reply, so I'll include alternate contact & details there if that's OK.

When I was looking into installing an SSD in mine I considered using a mSata->44pin adapter and connecting that to the cdrom port, but as it's such a non standard connector/pinout I abandoned that train of thought.

PC Hoarder Patrol wrote on 2023-01-14, 19:04:

Finally found the little beggar! 😀 ...it's the original cable from my own (currently busted) Deskpro SFF P3 450 - I replaced the original working CD-ROM drive and the new one came complete with cable.

Thanks to PC Hoarder Patrol's extreme kindness, I've now been able to replace the CD-ROM cable - it not only works perfectly - but - who'd have thought it - it seems to have greatly improved the "PC Thinking Noise" issue too! I guess where the old CD cable had worn through it had 'released' a lot more interference, nestled in right next to the internal speaker ...

The same day, the SoundBlaster Live! that I had ordered from eBay also arrived (an SB0220 - which I later learned is a model to avoid ...) and I've had some weirdness trying to fit it ...

First of all, I haven't been able to properly - when I disabled the onboard audio in the "Onboard Devices" section of the BIOS (cycle through several combinations of resource settings, last of which is disabled) - but even with it disabled in the BIOS (and the "Device Security" setting for audio enabled or disabled, whatever that does) - it still shows up - and works - in Windows.

I was able to install the drivers for the SB0220 using the driver file from the Vogons site, but when I rebooted the ESS card was still working, and in the Multimedia settings page in Windows only the ESS audio services were selectable for playback recording etc. I tried disabling the ESS devices in Windows Device Manager, which worked. But there still weren't any Creative devices in Multimedia Settings. So I thought I'd reinstall the drivers ... and that's when I hit something really weird ...

Since I installed the Creative drivers and rebooted - Windows hasn't been detecting any USB devices! At all! I even tried completely uninstalling the Creative drivers, but still zero luck detecting USB devices ... this does feel like a true reminder of Win98 days!

Any ideas? Is reinstalling Windows likely the only way to get USB working again?