INITIATE OPERATIONAL PROGRAMS

Figure 8-31.—Example of diagnostic error codes. code. Figure 8-31 is an example. You can use this error code for fault analysis. EXECUTE BOOTSTRAP. —Execute bootstrap works in a manner similar to the function on minicomputers. An NDRO is used to perform this function. The NDRO is tailored at the factory and will select a particular peripheral device (disk, tape, and so forth) based on the position of the bootstrap switches (0, 1, or 2) located on the computer’s controlling panel (maintenance, control, display control, or remote unit). To execute bootstrap, select bootstrap switch 0, 1, or 2 and depress the start switch (fig. 8-30). NDROs on mainframes may also be designed to perform a variety of tests or other functions that may be selected by use of the DIP switches. INITIATE OPERATIONAL PROGRAMS. — After the computer is booted, the operational program is loaded, initialized, and started. The operational pro- gram is tailored to meet the command’s operational require- ments or application. It is important that you know the software capabilities and limitations based on your hardware. Be sure your system is configured correctly. EXECUTE AUTO RESTART OPERA- TIONS. —Auto restart operations are used when power is restored after a power loss. EXECUTE DIAGNOSTICS. —External diag- nostics can be loaded into the computer, executed, and controlled using an external control device. They can also be loaded into the computer from a peripheral (disk or magnetic tape unit) but initiated and controlled by the computer. These diagnostics are very thorough. They offer the option of testing all or specific sections of a computer. They are more comprehensive than the BITs. Figure 8-32 shows an example of a defective card Figure 8-32.—Example of a defective card index (DCI). 8-25