Linksys WRT55AG v1.0
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This page reserved for Linksys WRT55AG only
Requires (*.trx) to flash
After flashing with the ASUS trx file, you can change to the generic VINT mini or standard using the Administration -> Upgrade Firmware tab, but whether you do that or not the 802.11a radio will no longer function, either way.
The devs are not interested in getting both radios on this working (Linksys DID release GPL source for this one, but not for v2; only 4MB of flash memory on both), so save yourself hours of frustration and just leave the stock firmware on it. If you're interested, you could salvage the 2 mini-PCI cards (one 802.11b/g and one 802.11a) from the inside... but you have to unsolder the hold-down clips to do that. Also, the swivel/jointed rubber duck antennae are not removable so nothing to salvage there, really. Rubber feet off the bottom, I guess.
Pictures of the insides are at http://www.dd-wrt.com/phpBB2/viewtopic.php?t=24378 for what it's worth.