Power-up Test Error Reporting Scbeme If a failure is detected during power-up diagnostic tests, the ACS 486 Monitor reports error(s) in following ways: A) The two LED's on the CPU board flash the Test Number that failed. NOTE The left (GREEN) LED, viewing from the front of the CPU board is the synchronizer, while the right (RED) LED pulses the Test Number in a five-pulse binary sequence beginning with the most significant bit.) example:
I Left-Green LED I on I on I on I on I onl 1----------------1----1----1----1----1---1 I Right-Red LED I offl offl on I on I onl 1----------------1----1----1----1----1---1 I Binary Code I BIB I 1 I 1 I 11 Test Number = 7 = Memory content test B) During system configuration reporting, the monitor reports all the failed components(s) on SIO (8274) port number I and the Diagnostic Console. Power-up Test Descriptions B,l) Prom Checksum Test - First, the low byte PROM of the Monitor PROMs is verified with the checksum. Then, the high byte is verified. By adding all bytes in a single Monitor PROM, a total sum of zero value indicates that the corresponding Monitor PROM has the proper contents.
2) Map Ram Data Lines Test - The test sends a single "1" bit across the data lines to check for a short-circuit among the data lines. The first location of map ram memory (I/O port Number BBBB) is used. 3) Map Ram Address Lines Test - This test sends data across the lower 8 address lines of the map ram memory to check for a short-circuit among the address lines.