Friday, November 28, 2008

easy scheduled shutdown for windows

I wanted the equivalent of shutdown -h 3600 for windows, googled and found that it is shutdown -s -t 3600. And \System32\shutdown.exe shows a dialog box counting down the time to shutdown too. shutdown /? for more options...

M-Audio MobilePre USB

Unfortunately seems to be el-cheapo in results too. Has -72 dB of noise - comparable to a normal PC sound card, not like Pro or Semi-Pro cards which have at least -84 like the Darla (a discontinued product now at ). But the real killer was lack of frame-accurate sampling. Drift of 0.3 sec in 30 minutes recording.

While doing the tests, played back drama CD with 13 tracks with the Marantz CD recorder (CDR 631)and recorded on saispace2 and sathya with the MobilePre and Darla cards respectively. The Darla recording synced with the CD audio captured using Cool Edit Pro's audio extraction, accurate to 0.02 sec over 70 minutes. The MobilePro had the 0.3 sec in 30 minutes.

Thursday, November 06, 2008

HP Pavilion travails

M brought a HP Pavilion dv6000 - dv6402ca to be precise - to check if networking is OK. He runs WinXP on it, and not the pre-installed Vista, because he has some sw which won't work with Vista. Found that the network driver was not installed - nForce chipset. Since the wireless was working, thought it would be a ten minute job to download the driver, install it and check it. Little did I know....

First, the Broadcom Wifi refused to work with our Airport wireless network. After entering the SSID and WEP key, a simple "Repair" was enough to make the Compaq connect to it. Tried removing the earlier configured wireless network, retaining only our home network. No go. Finally tried a restart. Voila! Connected. So, try try try again, if you don't succeed, restart!

The nVidia driver was a hefty 50 MB download. Got the link from

Unfortunately, Windows downloaded a couple of updates, and I thought I could club both restarts together. So, ran the nVidia driver setup and chose not to restart immediately, ran the update installation, chose not to restart immediately, then restarted. But then the screen remained black after the initial XP splash screen. Back-light is seen, but no display.

Tried Safe mode: login screen comes up, but keyboard and trackpad are disabled! Keyboard only works in the initial boot menu. Even attaching a USB keyboard didn't help. Turned in for the night on that note.

Maybe in normal boot, the new driver might be making the external VGA the main screen, thought I, so tried it out today with an external monitor. That one too showed exactly the same display as the built-in LCD.

Is it a hardware problem? Tried booting with Knoppix. What I had was an older version from Linuxforu, 3.2. It booted fine the first time, but reported that it found BIOS Bug #81[000...000] - Later rebooting worked only in failsafe mode. Anyway, it seemed there was no hardware problem. But couldn't do any repair of the Windows install from there, since it was on NTFS and this version of Knoppix couldn't mount the drive though it made suitable fstab entries.

Next option was to try Windows XP recovery console using my XP disk. Administrator password? It turns out the default is blank! OK, but what do I do next? Tried chkdsk /r - it found some errors and corrected them, but on restart, the problem remained.

According to this thread, instead of recovery console, I should try the Windows repair method:
.... would probably recommend that you just do a setup-mode repair by booting from your Windows CD.

Skip the initial repair console option and choose to install Windows. When it says there is already a Windows, would you like to repair it?, that's the repair you want. It will run a full setup and keep your existing Windows configuration. This will mostly back you out to the service pack that is on your CD and so you'll need to reapply updates and service packs (except of course the
offending one.)

If the setup won't repair your existing Windows because your current service pack level is too far past your CD, you'll need to first build a "slipstreamed" CD with Win2K SP4 or XP SP2 integrated into it. The information to do this is widely available on the web, or post back if you need to and I'll give you details. You of course need another machine or a separate, clean Windows install with a CD-RW to make this....

OK, worked as advertised, except... it asked for my XP CD key and then asked for activation! Yikes. Tried options from RB both of whose CDs did not boot, finally got a volume licensed CD from P. At last. After another round of "repair", it finally came up.

Then I had to install the network driver. After that installation, still the Network Connections was empty! When in doubt, restart; so restarted. But the Wireless Adapter was shown as driver not loaded, and the ethernet adapter driver also was not loaded. Tried deleting the devices in device manager as per the trouble-shooting wizard's advice. Then rebooting with the Wireless adapter enabled, successfully detected both wireless and wired connections. ]


Edit: And now the keyboard and trackpad work in Safe mode too.

Monday, November 03, 2008

setting up an Airport network with a PC

The old Airport Base station (graphite) needs a Mac for the configuration. Connected the base station and the iBook to a hub to which the ADSL router was also hooked up. Running the Airport Admin Utility, configured the Base station with appropriate ip address and so on, and enabled WEP. To make the PC connect, the WEP key has to be entered in hex: to get it in hex, one needs to go to the menu in the Airport Admin Utility and choose Network Equivalent Password. Once the hex key is entered in the PC, it connects just fine. This forum post which says XP requires 128 bit encryption is wrong. In my case, an added extra is an SSID which is not broadcast.

For setting up the connection, Network Connections -> Wireless Connection -> Properties -> Wireless Networks tab, add the SSID and the key. Once this is done, "Repair" option for the wireless connection makes it connect. In case a wired connection was active, the newly connected wireless connection may not be used as the gateway, a restart may be required.