NEWD or VINT
From DD-WRT Wiki
More recent wireless drivers are not compatible with older radio chipsets, so dd-wrt builds are made available in two different flavors for backwards compatibility with older routers.
Notes
DO NOT run NEWD on WRT54G v1.0 routers! Only install VINT builds. If you flash a NEWD build onto a v1.0 you will brick the router.
The command nvram get wl0_corerev
can also be run from dd-wrt's GUI on the Administration->Commands tab.