Thanks to Mark Wallis, I now have the RS232 level adapters for using the serial console on the Agestar NAS box I bought from Jaycar earlier (see here). I spent way too long fiddling around, trying to solder breakout pins, and then trying to find the correct pin connections between the Agestar and the serial adapters. (Remember the good old days when the red wire was Vcc and the black wire was ground? It also helps if you have a working serial port in your workstation…)
For reference, the UART pins on the Agestar are: pin1==Rx, pin2==Tx, pin5==Vcc (3.3v to the level converter), pin6==GND; console at 38400 baud, 8n1. The level converter has brown == GND, orange == Vcc, red == Tx, black == Rx (you would connect its red wire to pin 1, and so forth).
From looking at the firmware I downloaded before, I was expecting to just get a boot monitor command line. But better than that, all the system booting output appeared, and finished into a busybox shell! … I saved a bit of system information to this file: agestar.internals.txt
With 32MB of RAM, 16MB of Flash (available as a regular ext2 filesystem), onboard host USB, IDE, and SATA connectors, and completely unfettered access to the system (once you’ve got a serial console..). The factory firmware includes Python 2.4 too. This little cheap Agestar is quite a nice, cheap, easy Linux-based hackbox. :-)
Update 2008-05-16: I had a request for a close-up photo of the serial port connection.