Geoff Beasley wrote:
>> Maybe some deeper way of
>> manipulating the IRQs that I'm not aware of?
>
> nope.looks like it's hardwired.
>
indeed. - they "might" be firmware-programmable, but usually they are
hardcoded in the PCB. - in a few years your kid might find DIY
instructions to how to tweak that old R60.. ;)
>> I'm planning on getting a PCMCIA sound card at some point, but after
>> dropping 1,400 on this laptop my extra funds are a little tight for a
>> while.
PCMCIA is ok, but not great for low latency. (adds one extra interface
between PCI bus & sound-card). - the cheap solution is to get a PCMCIA
card for your hard-disk - instead of using the built-in firewire for the
disk. - maybe you want to do that anyway. use the built-in firewire to
an external audio-device and the PCMCIA for storage.
> go usb. better supported and cheaper too probably.i use a m-audio transit.
> works well.
>
usb will get you only 2 channels (full-duplex @48kHz, or half-duplex at
96kSPS, due to USB1.1 bandwidth limitations. IIRC there's no USB2-audio
standard.
The hardwired thinkpad PCI-IRQ's are a bit annoying for pro-audio, but
after all it's possible! - thinkpad X60s (guess it's similar to the
R60): the build in hda soundcard works fine with
`jackd -R -P70 -dalsa -dhw:0,0 -r48000 -p64 -n3` !!!
but the sound quality is.. mmmh great for telephone & entertaining music.
If I use the wireless (ipw3945 - same IRQ) extensively I get xruns.. a
Firewire drive might cause similar issues, I have not tested that. - The
easiest solution is to connect your firewire disk to a 2nd machine and
export it via eth-wire (or USB?)
If you are into hacks&tweaks you might be able to get a useable system,
though: tweak the PCI bus settings (try the inverse of what paul's
setpci script does: If the firewire device blocks the bus for too long,
the audio on the same IRQ won't have a chance.), disable DMA for the FW
harddisk (is that possible? - maybe try different IO schdulers or limit
the disk-i/o bandwidth in favor of polling it nicely?, does the
fw-device driver have a PCI/split-transaction on/off option?) - IIRC
there's a way to re-nice kernel threads, but nothing that any sane
audio-engineer would want to try...
As for Sound: I rarely use the SD-reader (sdhci:slot0 - BTW. unloading
the module saves power!) so I connect a USB UA-25 to either IRQ22 or
IRQ23. even if it's the only device on that bus I get rare xruns on 64
frames/period. but a robust setup with `jackd -R -P 70 -d alsa -d hw:1
-p 256 -r 48000` makes this Thinkpad a great machine for
stereo/binaural audio work and fun! - (recap: the Dell D820 seems
somewhat better suited for pro-audio, and a Vaio sz3 is similarly good,
but sony&linux requires a little more some devotion..)
thinkpad x60s:
CPU0 CPU1
0: 352029528 0 IO-APIC-edge timer
1: 1251013 0 IO-APIC-edge i8042
8: 0 0 IO-APIC-edge rtc
9: 65043220 0 IO-APIC-fasteoi acpi
12: 10126775 0 IO-APIC-edge i8042
20: 35583442 20485440 IO-APIC-fasteoi yenta,
i915@pci:0000:00:02.0, uhci_hcd:usb1
21: 200293604 250337407 IO-APIC-fasteoi ohci1394, ipw3945, HDA
Intel, uhci_hcd:usb2
22: 65491123 0 IO-APIC-fasteoi sdhci:slot0, uhci_hcd:usb3
23: 745166 1065462 IO-APIC-fasteoi ehci_hcd:usb5, uhci_hcd:usb4
218: 1670650 179 PCI-MSI-edge eth1
219: 810037 3174745 PCI-MSI-edge libata
NMI: 0 0
LOC: 107326912 241228138
ERR: 0
MIS: 0
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