IBM System/23 Datamaster: Difference between revisions

The System/23 Datamaster implements a set of self-test routines identified as "PID-1200". With them it tests the CPU, the memory and the different peripherals of the computer. Usually the results of the tests are written to the screen at start-up but if an error occurs before the initialization of the screen a probe is needed. Faulty CPU, ROM or 8255 (units 2 and 3) will prevent any diagnostics to be displayed, even with a probe. The tests are identified by an hexadecimal value and can be presented unstyled, underlined or inverted. In the case of being underlined it means that the feature tested wasn't found by the system, whereas if it is inverted it has been detected but was tested and found faulty. If the text is left unstyled, it means the test passed. The test routines and their tested areas are the following<ref>6841631 System/23 Diagnostic User Guide, page 87</ref>:

| 05 || CRTC, DMA || Interrupt test; initialization of 8275, 8257; light pen test. It fails with standard 8275s.