DustyShinigami wrote on 2026-02-04, 22:21:

I dIdn't fully process this earlier, but this. I think this is the reason. My PC speaker is missing/disconnected. I can't remember if my main motherboard ever did it, but the one in my test rig does.

Do you have an actual speaker connected to the SPK header on the mainboard? It's usually ganged together with the front panel button/light headers

Many boards do not populate the speaker anymore.

You can get tiny peizobuzzers on a 4pin dupont connector from many places though. It wont sound the same aa an old paper cone pc speaker, but those are getting hard to find.

https://www.amazon.com/RuiLing-10-Pack-Comput … /dp/B07T7V2RKB/

For example.

Okay, it turns out I'd plugged the speaker cable in wrong after assembling everything the last time. Put it in right and it works! Although my rig actually does the beep right during the initial boot, a few seconds after pressing the power button. So not directly after the floppy boot seek, which is what my test rig does. And that's the sort of time I'm familiar with. I'm guessing there's no way of changing that...? The BIOS is clearly doing that as the setting is enabled, but I'm not sure if BIOS extensions are possible with this system.

There's no way to change that, it was up to the manufacturer to put the beep at successful POST which is common in newer systems or somewhere later in the process which was typical of earlier systems. They pretty much always left the beep at the default location that came with the BIOS. It probably could be customised with some BIOS hacking but it doesn't really seem worth the risk to shift a beep by a couple of seconds.

Ahh, I see. Thanks. At least this thread helped me identify that it wasn't connected correctly and that it should've been doing it all along. Just in a different place.

Yea, the bios extention sounds legit.

Raise the temperature of the XUB crowd by hacking it in there and submitting a pull request…

That's a bit beyond my expertise, I'm afraid. ^^;

DustyShinigami wrote on 2026-02-05, 00:06:

Okay, it turns out I'd plugged the speaker cable in wrong ...

Ok, this should have prevented you from hearing *any* beeps from the PC speaker.

A number of DOS utilities beep via PC speaker, but I guess if you are running Win? or apps(eg:games) with sound-card audio output, you might not have noticed?

DaveDDS wrote on 2026-02-05, 19:53:

...

Sorry, this was an accidental repost of my previous one (quotated!) - ignore

DaveDDS wrote on 2026-02-05, 19:53:

DustyShinigami wrote on 2026-02-05, 00:06:

Okay, it turns out I'd plugged the speaker cable in wrong ...

Ok, this should have prevented you from hearing *any* beeps from the PC speaker.

A number of DOS utilities beep via PC speaker, but I guess if you are running Win? or apps(eg:games) with sound-card audio output, you might not have noticed?

Both Win and DOS games. I've been installing, configuring, and play-testing them. As I mentioned earlier, the only utility where I noticed no sound emitting from the PC speaker was in SETYMF, which I thought was a bit odd. Can't say I noticed any game have issues though.

DustyShinigami wrote on 2026-02-05, 20:01:

... the only utility where I noticed no sound emitting from the PC speaker was in SETYMF, which I thought was a bit odd. Can't say I noticed any game have issues though.

Assuming the games are complex enough to play audio via a sound card (or motherboard sound card equivalence), it is likely that they play all sounds that way (much easier to mix, control volumes etc.) - it's typically only basic DOS tools that beep via the speaker. If all you need to do is "beep", it's far easier to do so by interfacing to the internal PC hardware to drive the speaker (just a timer chip and a gate to the speaker) than to interface with an "unknown" sound card driver. (or even easier, just send 0x07 to the DOS console character output function - you of course don't have any say is what the beep sounds like in that case - but if all you want to do is "make a noise"...)

FYI, the ASCII "BELL" character (0x07 - Control-G) originated in the days of mainframe/mini computer which were typically accessed via a RS-232 serial connection (direct or dial-up modem). The only communication you could "display" or accept was 7/8 bit characters, and ASCII standardized on the BELL (0x07) code to sound a beep - and makers of "one after another" character oriented displays tended to follow that convention.

The idea of "BELL" came from teletype systems which pre-dated computers and ASCII - in most cases the entire "terminal machine" was implemented mechanically (lots of gears and levers, no CPU) - these typically used a 5-bit "BAUDOT" serial code stream, and one of the codes "BELL" triggered a solenoid which rang a physical Bell!

[You can see such a Teletype on "Daves Old Computers" -> "Altair" -> "Photos of complete system"
There is a photo in that collection of the system I had before the Altair - a homebuilt 8080 - in that pic is a Model-28 teletype machine]

DaveDDS wrote on 2026-02-05, 22:10:

... a homebuilt 8080 - in that pic is a Model-28 teletype machine

Bit of am "interesting" story behind that machine and it's connection the it's "printer".

This was the first significant system I ever built - and I wrote all the software it ran.

At that time (some of my earliest code), I didn't use "interrupts" - in fact the CPU IRQ input was hard-wired OFF in that design.

The 8080 has a IE (Interrupts Enabled) output bit which is ON when interrupts are enabled and OFF when interrupts are disabled.

Which made a quick and easy way to pulse out the 5-bit baudot codes to the teletype. So my OS had a function which sent a character to the printer by 1)Translating it to baudot, then 2) enabled and disabled interrupts to raise/lower IE line in the right sequence to send that code to the teletype! (yeah, a LOT of my "computing firsts" where through that system)

As usual, thanks for the insight and history. 😀 For 90s era systems, was the bell/beep command used more for testing purposes?

One thing I have noticed is that POST beep never happens if I restart the PC. Only if shutdown and powered on.

Some bioses beep only on cold boot, not warm boot.

The bell is just to draw attention. (Or annoy)

A useful use case would be to beep after some task that takes long completes.

Ahh, I see. Thanks.

The BELL character was most used by OSs with a simple TTY oriented console user interface (like DOS)
- This is also why BIOS typically used it - the OS hasn't started yet and it's a simple text mode interface (although I've seen BIOSs with full graphical interfaces and sound support)

OSs with audio/sound support (like Winblows) typically play "unique" sounds to draw attention to certain events.

Examples of a TTY oriented OS/APP sounding BELL might be:

1Bad or otherwise error comamnd.
2Entry of wrong key when prompted for one of a specific set of keys.
3Termination of an important or lengthy event.

And... there were no "standards" ... some software sounded BELL at places where others might not.
It really was a way of getting attention, just like some software might display errors like:

1ERROR: message
2***ERROR*** message
3The "message" error has occured.

In other words, it was up to the program designer.

Indeed.

Some linuxes beep in text mode (runlevel 3) when you tab auto complete commands where the autocomplete partially completes up to a point where there is more than one possibility going forward. First tab beep, tab again display possibilities.

Some pc speakers are quite loud. Imagine the fun for everybody else, tapping away at such a console late at night…