I pretty much daily use a Tech-Tools logic analyzer (http://www.tech-tools.com/dv_dv1.htm ). It decodes async, spi, and I2C along with showing bus and boolean signals. Works well for me! Harold -- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available! -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist