In this collection of items we have two OS-65U Operators Manuals from June 1978. These manuals cover System and CD-74 Initialization, Utility Programs and Reference Tables. We also have two copies of the Ohio Scientific's Disk Basic Reference Manual from November of 1978. This manual provided detailed information about features in the language which are unique in the particular version of BASIC. Included in this collection are two Peek 65 Journals which were the Unofficial OSI Users Journal. A Product Bulletin for the Challenger C3-C is included as well, explaining the powerful, mid-size member of the Challenger family featuring OSI's unique double processor architecture with 52K bytes of RAM and a 40 megabyte Winchester hard disk drive. The last item is a programming workbook for the 65V Primer computer that contained exercises in machine code using the machine's built-in 65V Monitor ROM.