Power Mac 6500 audio in BeOS?

Be, Inc.
#1

Picked up a 6500/275 since I wanted a tower system and there was one for a non-confiscatory price. It works fine in Mac OS 8.6, including audio. It has the AV inputs, but no AV out (other than the usual audio jacks).

In BeOS R5, it mostly works great. The Twin Turbo card works, the DEC 21140 NIC works, it’s nice and zippy with a 1MB L2 cache card, but … the audio doesn’t work. I even tried turning SRS surround off in MacOS to see if that was affecting anything, plugging in headphones, external speakers, nothing. It’s silent as a post in BeOS.

Anyone have a 5500, 6500 or TAM running BeOS? Does audio work for you?

#2

Just a followup, though this is still not fixed yet:

  • Upgraded to 5.0.3. No difference.
  • Found a 21040-based CS II Ethernet card in my parts drawer, pulled the AsanteFast PCI NIC and the old 6500 GeoPort modem in case the soft modem was messing with the audio, and installed it to see if it made a difference. BeOS happily used the new Comm Slot Ethernet (since CS II Ethernet looks like a PCI card) but stayed mute.
  • Since I now had a working serial port with the GeoPort modem out, I plugged the PowerBook 1400 into the 6500’s serial port, started ZTerm on the 1400 and brought BeOS up on the 6500 with the kernel debugger. The debugging output was copious but I saw nothing related to AWACS, and I didn’t see media_server or media_addons_server anywhere in the output either. Should these appear if they’re being properly initialized? Restarting the Media Server also generates no debug output (other than the usual launch and patch messages).
  • I attempted to play BeBeep.wav and BeStartup.wav in Media Player. Media Player says there are no codecs available and won’t even display them. Modulo updates in 5.0.3, the contents of /boot/beos/system/add-ons/media is identical with my working BeBox. Is this an actual problem, or is this just a symptom of sound not loading?
  • I attempted to play a MIDI file in Simple Midi Player. This does try to play it, and the oscilloscope looks like audio waveforms, but the machine still remains mute. The same file plays properly on the BeBox.

Like I say, audio works just fine in Mac OS 8.6. The only thing that makes me hopeful is when I click mute on and off in Media Preferences, I can hear a pop like the volume got initialized when I wear headphones.

Does this point to any particular issue? What should the kernel debugging output look like with working sound on a Power Mac?

Since I now have a PCI slot free, I suppose I could add a sound card, but I suspect what the x86 and PPC builds support is rather different.

#3

You could try enabling the old Audio Server (or disabling it.)

I don’t have one of these, but the two Macs I do have both have sound (9500 with multiprocessor card and a UMAX C500 clone.)

I think the only person I know with some kind of Mac like you mention is @cian

#4

How do I do that? Never had to before :slight_smile:

I’ve actually been talking with him in E-mail, but he has a 5400. I wonder if the difference between Alchemy and Gazelle boards is the problem. I have a TAM also, which is the same board, but it has a L2 G3 and runs 9.2.2 and I don’t feel like breaking that all down just now to try to boot BeOS on it.

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#5

The L2 G3 should work in BeOS; but I’ve not been brave enough spend the $500 they now go for plus shipping plus customs to try. 9.2.2 is still an issue of course.

#6

For what it’s worth, the 6500 is noted as unsupported but compatible in the official compatibility list, as are others you mentioned (5400/5500/TAM).

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#7

I’m aware, and I’m suspecting the Gazelle boards just don’t work completely with BeOS at this point. I suppose I should look at PCI card options since I’m not going to junk this after the time and money I’ve sunk into it so far.

#8

There’s some specific handling for Gazelle cards in the Linux driver; although I knew a 5500 owner that had no issues in BeOS.

#9

Someone running BeOS on a TAM and no audio:

#10

An intermediate followup. Since the sonic_vibes driver is built on PowerPC, I got an S3 Sonic Vibes PCI card and installed it, and nothing happened (it wasn’t even detected, even when I blew away the AWACS driver to ensure it wouldn’t conflict). Bringing up the kernel in debug mode showed no output.

After some thrashing around in the kernel debugger, I found the issue is that the Mac kernel doesn’t seem to support the gameport or MPU-401 (the BeBox does, so it would load there). Monkeypatching the driver to work around this – after recovering from a kernel crash on my first attempt – causes it to load PCM and mixer support, but the machine is still mute no matter what output I connect to on the card. It’s possible it never worked with anything but the BeBox.

So I guess I’ll thrash around some more with the AWACS driver and see what I can do with that.

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#11

As another datapoint, this user ( BeOS Install | TinkerDifferent ) has working sound on their TAM. But they seem to have the same loadout as the tweet (250MHz TAM, 64MB of RAM). I wonder if there are differing logic board versions; similar differences affect other supported models.

#12

Hi! I have a BeBox (Dual PPC 603e, 133MHz) and a Power Macintosh 4400 (PPC 603e, 200 MHz). The BeBox has a Crystal CS4231 sound chip and the PowerMac has a Crystal CS4217, both chips are working fine under BeOS. You could try to find an old PCI sound card based on Crystal chip (4XXX series) and test it on your Power Macintosh 6500. They were very common and cheap cards.

#13

I appreciate it, but the 4400 should work because it’s a supported system (the 6500 and TAM technically aren’t). As far as the PCI option, I’d have to write a driver from scratch for it. I may end up doing that but I’d rather get the on-board AWACS working first. Right now I’m working from the theory there are differences in logic board revisions, since some work and some don’t.

#14

Okay, because I just can’t ever let anything go.

On TinkerDifferent someone reported their 6500 (a 225MHz) had sound (this is a 275MHz). I pulled the cache card to ensure that wasn’t a factor; no difference. Their AWACS driver binary is the same. However, they used the Gobe 5.0.3 image from the Internet Archive instead of the official 5.0 I had that I then upgraded to 5.0.3 (though neither version worked).

I installed the Gobe 5.0.3 on another partition. There was still no sound through the main speakers, but … the front headphones work! Well, sort of. They’re very scratchy like the sound is being overdriven but BeBeep and BeStartup are recognizable and at the proper pitch. Turning down the master and mixer volumes just made them scratchy at lower volume. Also, restarting media_server causes it to go into a crash loop.

But, anyway, this is progress. I compared /boot/beos/system on both partitions. There are different files in add-ons/media/{decoders,extractors,writers}, different add-ons/media/{decoder,extractor}.media_addons and different csedv-c.so, libbe.so and libroot.so (and .xMAPs).

I have AWACS register documentation, but not for the 5500/6500, so I need to sit down and look at how the Linux driver handles the headphone port since that appears to be the gap that’s missing.

#15

Regarding scratchy audio - could it just be an issue with your logic board? My C500 audio is scratchy (well, not is I pull all the PCI cards) so I just assumed a capacitor was probably on its way out. Might also explain why it partially works… maybe?

#16

It’s possible, though the Linux AWACS driver does a lot of screwing around with the headphones on its 5500 path, so maybe the same thing needs to apply. The problem is that file is very difficult to follow. I tried asking the author about it but didn’t get a reply (may no longer be at that address, it’s obviously not a new file).

#17

Made progress on this: I have audio through the speaker now! More soon.

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#18

I have a working driver. Audio still isn’t ideal, but I think this is the media server’s fault (or at least partially so). Download links in the article.

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#19

Terrific writeup!
But gopher… Why not set up distribution by 720k floppies for a true old-fashion feel?