xerox Disk Diagnostic Feb78 free download

File name Disk_Diagnostic_Feb78.pdf

Inter- Office Memorandum To F Ludolph Date February 13, 1978 From JR Cucinitti Location Palo Alto Subject Disk Diagnostic Organization SDD/CS/SD XEROX Filed on: (Cucinitti) Diskdiag.memo The Disk Diagnostic pack has two diagnostics written in four different places in anticipation of loosing one or more of them. One diagnostic is booted by using just the boot button in the first case. and depressing the 0 key and pushing the boot button in the next. The other diagnostic is booted with the K key and boot button. and the V key and the boot button. The diagnostic booted with no keys and the 0 key will write one pass on the disk and then start into a read loop. we call it write once. read forever. To run the diagnostic just type 40001B (this sets an error breakpoint), 40000P (sends the Alto to 40000 to fetch the first instruction). The diagnostic booted with the K or V key will write. read. write. read... To run this diagnostic type 1001B (sets the error breakpoint). 1000P (fetches the instruction from 1000). To halt the diagnostic just depresss the Swat key. this will display four registers, to continue depress the P (procede) key. The knowledge of the location of the diagnostics in the Alto memory is of some use. The diagnostic booted by the 0 key resides from 40000 thru 42154 and uses memory locations from 1000 thru 37777 for the data handling area. The diagnostic booted by the K key resides from 1000 thru 3153 and uses 40000 thru 176777 for the data handling area. The first 777 locations are used to run the display and keyboard and should not be changed. You may note that the listing does not reflect the true memory locations but do indicate the locations relative to the starting locations of the diagnostics. The debugger located in the first 1000 locations will allow you to modify any memory location and remember it only knows about octal numbers. The commands to the debugger are: nl opens and displays memory location n cr inserts the typed information in n and closes the location .. modifies. closes location n. and opens location n+l 1" modifies. closes location n. and opens location n-l A displays accumulators 0- 3 nB set a breakpoint at location n nD deletes breakpoint n (1- 9) nP procede from this location When you do get an error you will see something like this: DATA COMPARE FAILED 0:123456 1:123455 2:012345 3:001612 ACO