A few photos of a nice IBM XT model 5160 with 10mb hard drive, CGA display, and AST Six Pak RAM and utility card. Click image for larger view.

A view with the top cover removed. All components are original. AST made a fortune selling their add-on cards, which were often purchased to expand the system at a lower cost than IBM's expansion cards. The capacity of this 5160 motherboard was 256K, the Six Pak contributes another 384K plus serial and parallel ports.

Pictured is the opening screen for IBM's Rocket Lander Version 1.0. This program was typical of the BASIC programs and sets sold by IBM. IBM optimized them for DOS 1.x or 2.x systems, BASIC version, and system capabilities. 30 years later one finds a mixed bag of these early BASIC games, demos, and programs floating around.
Another factor is that IBM sold versions of BASIC.exe and then BASICA.exe to run these programs. I have discovered that the programs do not work correctly on both versions. You have to try both.