Someone generously gave me an FSLBOT and I ported StickOS BASIC to its TWR-MECH board (it was an easy port since StickOS BASIC already ran on the TWR-MCF52259).
StickOS BASIC is an MCU-resident interactive embedded system programming environment intended for hobby and education use, including an easy-to-use editor, transparent line-by-line compiler, interactive debugger, profiler, and flash filesystem, where external MCU pins can be mapped to special "pin variables" for manipulation or examination, and internal MCU peripherals are managed by BASIC control statements and BASIC interrupt handlers.
For this port I changed the PWM resolution from 8-bit to 16-bit so that you can have fine-grained servo control (0.3 us), and also added BASIC library support, so that you can call subroutines to manipulate board components that are stored in a library in flash (outside your main program).
There's an intro article on StickOS BASIC here: http://www.towergeeks.org/forum/topics/introducing-stickos-basic-for Since that post, I previously added support for i2c, spi, lcd displays and scanned keypads, as well as character strings and better input/print control.
And you can find all the bits and documentation here: http://www.cpustick.com/index.htm
To raise and then lower the robot's left foot is as easy as (totally interactive, from the command line):
> dim leftfoot as pin dtin0 for servo output
> leftfoot = 1000
> leftfoot = 1500