Hi, I tried to report bug to the bug reporting system, however, I didn't have the username/password to summit the bug. I recompiled the insight-5.1 by arm-elf configuration, use the target ARM Angel/Serial, baud 57600, com1 to connect to the ARM Evaluator-7T target board. The scanf() always return -1, so I can't get the input chars. However, the scanf() works fine on the gdb-5.1 Did you know how to solve this problem ? Best Regards ! Jason Lin Department Manager uC Business R&D Division Dept. III PC30, No. 4, Creation Rd. III Science-Based Industrial Park Hsinchu, Taiwan, R.O.C. Tel: 886-3-5792738 Fax: 886-3-5792766