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Streaming RealAudio From a Commodore 64
An anonymous reader submits: "This just came in on comp.sys.cbm and
I think it will be of general interest here at Slashdot as well. Two
Commodore hackers, Adam Dunkels and Peter Eliasson, have built an
Ethernet card for their C64 and have connected one to the
Internet. But they aren't 'just' running a TCP/IP stack and a web server on it - they are also
running a RealAudio server which streams audio from the C64's cassette
player and apparently, it sounds awful! They have the full source code
avaliable and pictures of the
C64 server."
On the whole, lots of peripherals and expansion cards back then had ridiculous amounts of processing power. For example, the floppy drive usually used on the C64, the 1541, had a 6502 processor (a slightly older version of the 6510 used in the C64 itself). C64 facts from here. The floppy drive was connected to the machine with an insanely slow serial port, so it had to work more or less autonomously.
The silliest example of over-powerful peripherals has to be the General Sound card for the ZX Spectrum. The General Sound contains a 12 MHz Z80 and 128 K RAM, upgradable to 512. The Spectrum contains 48 or 128 K RAM (256 or 512 on some clones) and has a 3.5 MHz Z80 (7 MHz or more in some clones). In other words, the sound card (which is fully programmable) is more than 3 times as powerful as the machine it's connected to. General Sound info here.
For today, ponder the latest 3D graphics accelerator.
As one of the guys who made this, I must say that I am amazed to see how well our C64 server is handling the Slashdot-effect. With a little more than 50 comments, I still can load parts of the first page.
The web server that runs on port 80-84 actually implements a simple form of overload protection and during testing, we managed to serve 8000 pages over a period of 30 minutes. That makes 4 pages per second! Note that it is only the first page that is overload protected, so the other pages will still load very slow (if they will have a chance to load at all!).
The real-time streaming audio server is running on the same machine as the web server so nobody will probably have a chance to hear the audio stream.
Furthermore, the headline is wrong - we are not streaming RealAudio. We are streaming audio using the open RTSP/RTP formats that RealPlayer and other players can handle. The RealAudio file format is secret so we would probably have been sued if we had been streaming that.
Finally, here is Google's cache of our newsgroup announcement.
They didn't they implemented a version of the standard RTSP/RTP protocal. This is an open standard similar to TCP/IP standard. It just happens to be the standard that Real Player uses for its protocal.