PropDOS can be obtained by downloading it's current source:  (Re-configurable)

PropDOS can also be obtained on EEPROM from uController.com.

EEPROM versions allow instant use of PropDOS without the requirement of a PropPlug to get started.

Because PropDOS is based on the free work of many programmers, it may NOT be sold for more than

the following:  Actual EEPROM Cost+$3.00+Actual Shipping Cost

This allows anyone providing PropDOS on EEPROM to re-coup their costs involved, not profit.

For discussion or download of PropDOS, visit: http://forums.parallax.com/forums/default.aspx?f=25&m=224206

SpinStudio boards with PropDOS installed can be purchased here