MythTV and AM2 on Linux war stories, a continuing saga

by Nicholas Petreley

As you may recall from my last entry, I exchanged my cable box from a Scientific Atlanta 8000HD to a Scientific Atlanta 8300HD. The latter, new box continues to output a signal from the cable connection even if I have it in HDTV mode. It probably also continues to output AVI and S-Video. This finally opened up a way for me to use my cable box with a MythTV box.

Thanks to a serious (and mysterious) spinal injury (I say mysterious because I haven't figured out how I did the damage), I can only work on the project for a half hour at a time, at most. I have discovered some interesting things in those short segments.

First, the cable box is outputting a digital cable signal. It may even output an HDTV digital signal, but I haven't determined that yet. I discovered it wasn't putting out an analog signal because it didn't work with my Hauppauge PVR500 card at all. The Hauppauge card looks for an analog cable signal. The Hauppauge card also has S-Video and AVI inputs, so I could probably still use it. But I wanted to confirm that the cable signal was digital, so I pulled out the Hauppauge card and and replaced it with the pcHDTV HD5500 card.

MythTV DVB support

Ubuntu 6.06 recognized the pcHDTV card and loaded the drivers. I figured I was home free, but I couldn't get a picture from this card using "tvtime" ( a simple tv-watching program that is good for testing things like this). Ubuntu doesn't seem to come with the firmware for the pcHDTV card. The pcHDTV card comes with its own drivers and firmware, but I couldn't get the pcHDTV drivers to compile with the stock Ubuntu kernel.

The fact that tvtime didn't work tells me that the drivers weren't working, but I figured I'd try MythTV anyway just in case. It didn't work, and it complained that it wasn't compiled with DVB support. I recompiled MythTV after configuring it with --enable-dvb (and another necessary switch that escapes my memory at the moment). That didn't help, but I didn't think it would. The driver was the issue.

Digital signal confirmed

I may go back to the HD5500 card at some point, but I read that Ubuntu works with the Fusion HDTV5 RT Gold card "right out of the box", and I happen to have that card. So I plugged in that card. I ran "tvtime" just to see if I could get a picture. Lo and behold, it works. The picture is terrible (too bright, washed out, not quite synced), but it's there. So I proved to myself that the cable box is putting out a digital cable signal.

That was all I could handle, given that my pain was reaching new heights by the time I finished this step. At this point, I have the option of looking into how I can fix the quality of the Fusion card, or I can install a vanilla kernel and compile the pcHDTV drivers (I've done it before with a vanilla kernel and made it work, so I know this is possible).

Regardless of the path I choose, I'm pretty sure I can use the USB-based IR receiver and blaster that came with the Hauppauge card to make the remote control change channels on the cable box instead of the card. But I want to get a card working, and working well before I even try that.

More APIC madness

I put together another socket AM2 box for someone. I've built so many boxes that I'm beginning to break records on the time it takes to assemble one. So I had it up and running before my pain level hit the breaking point. This box uses the Gigabyte GA-M59SLI-S5 motherboard. It's a very nice motherboard and has great on-board sound. I'm a bit jealous since the ASUS M2N32-SLI Deluxe sound borders on crappy.

Regardless, the Gigabyte board has the same problem as the ASUS board with respect to IO-APIC. Linux can't connect the timer to APIC and refuses to boot. The only way I can boot any Linux kernel, including the latest 2.6.18-rc4, is to use "noapic" as a boot parameter. I tried using apic=debug, but it didn't give me much information. It simply told me that it tried to associate APIC with two different timers, and failed on both.

To be continued...