Abstract: A method and apparatus is provided for upgrading software, or a portion thereof, on a continuously running system, while the system is operating. A base set of software is built which contains a reserved memory area in its memory architecture. Upgrade source files are built into the reserved memory area. The upgrade images are extracted out and converted into loadable upgrade images. A header indicates where the upgrade is to be downloaded in the system and also identifies the location in the reserved memory area at which the upgrade is to be stored in the relevant component of the system. The upgrade is downloaded into the respective reserved memory area in the memory storage devices in the respective components in the system. The downloads can be performed while the system is operating because the reserved memory area does not contain live code. The upgrades are activated or deactivated using a jump instruction sequence.

Abstract: A focusing solar collector which utilizes an elongated parabolic shaped mirror made from a sheet of drapable material so that when draped in a catenary like curved configuration, the sun's rays may be focused on a linear target which is axially aligned with the axis of the mirror. Means are provided for adjusting the angle of the drape of the catenary like curve in order to maintain the focus of the sun's rays on the linear target as the relative diurnal position of the sun to the collector changes. The optimum catenary like curve for the range of the drape angles involved is achieved by using a non-linear distribution of weight along the cross-section of the draped mirror material.