FIELD SERVICE SOFTWARE ASSISTANCE BROCHURE O S - 8 Prepared by: Rick Moore INTRODUCTION This is a reference document for Field Service use in diagnosing system problems. The information presented in this chapter is extracted from various OS-8 reference manuals and literature which are listed in the appendix. It is not intended to be a course on OS-8 or a substitute for standard DEC software manuals. However, the topics presented here are some of the more commonly used features and some of the commands that should help you to better serve your customer through an enhanced knowledge of his OS-8 operating system. It is strongly recommended that you be extremely careful using your customer's software as a little knowledge is a dangerous thing. If you do work on a customer's files, be sure to use copies of his system only. Tell him what you feel the problem is and let him take any corrective action. OS-8 consists of an executive and library of system programs which reside on a mass storage device called a "system device". This could be a disk, dectape or floppy unit. The executive supervises the overall program processing and consists of the following four major components: - Keyboard monitor ( KMON ) - Command Decoder ( CD ) - Device Handlers - User Service Routine ( USR ) The Keyboard Monitor provides communications between the user and the OS-8 Executive. The root segment of the monitor resides perminently in memory and occupies 256 words. Commands from the console terminal are interperted and whenever needed, the Command Decoder, USR, KMON, and ODT are brought into memory in a series of overlays while the contents of the memory used is swapped out to the system scratch area. In this manner it is possible to run a baseline system in only 8K words of memory. The commands that are executed directly from the KMON are: ASsign - assigns a new, user defined device name to a perminant device. DEASsign - restores perminant device names GET - loads core image files into memory from a device START - starts execution of a program already in memory RUn - loads core image (.SV) files into memory from a device and starts execution R - loads core image (.SV) files into memory from the SYStem device and starts execution SAve - creates core image programs on a device ODt - invokes the Octal Debugging Technique DAte - sets / prints the system date The Command Decoder is called when a system program needs additional information from the operator concerning files to be acted upon or devices to be used. You are in the Command Decoder whenever the prompt character "*" is issued. Understanding the Command Decoder line format is probably the most important step to successful usage of the OS-8 Operating System. It is as follows: *OUTDEV:OUTFIL.EX