Hi! On PowerOn my C167CR-LM should do some RAM-checks. Writing procedures for testing external RAM and nonvolatile RAM (using idata-Variables and internal registers) is done, but how can I test the internal area? I'm using the following tests: 1st: Walking 0s/1s over the adressbus 2nd: Simple Adress-Test over der whole external RAM and NVRAM (writing their own address into each cell and checking it after all cells were written) .. this test is done 3 times by Byte-shifting the addresses 3rd: Cell-Test (writing 0x55 / 0xAA to each location and testing them after all cells were written) Is their a GOOD non-destructive RAM-Test or how could I do a destructive IRAM-Test on PowerOn? Thanks for any answers Torsten