Permit me to add the following suggestion for inexpensive PC oscilloscope packages: BSOFT Software, Inc. 444 Colton Road Columbus, OH 43207 Tel. 614-491-0832 FAX 614-497-9971 The package that I use includes their ANA150 analog/counter PC compatible board, which the product sheet describes as follows: "The ANA150 is a low-cost, fast, reliable, and easy to program (you don't have to do this if you use PC-SCOPE described below) 8-bit (flash) data acquisition board that is a perfect industrial or laboratory tool for students, educators and engineers. It features eight analog input channels with a conversion time of 2.5 microseconds and 3 individual 16-bit counters. "The ANA150 can accurately digitize a single channel of 0 to +5 volt signal to a 19.5 millivolt resolution in only 2.5 microseconds, for a throughput of 400,000 samples per second. "The 3 16-bit counters can be used for generating square waves, providing an accurate time base for data acquisition and/or numerous counting operations." Integrated with the ANA150 board is BSOFT's PC-SCOPE software. The following PC-SCOPE features are listed: "1, 2, 4 or 8 channel operation. Complete sample data files can be saved for future viewing. Optional selection of a channel's trace color. Optional selection of a channel's trigger edge (rise or falling). On screen time base divisions from 1 usec to 500 hours. 45 time base settings (usec/div, msec/div, sec/div, min/div, hr/div). Any part of signal can be zoomed in or out. A/D conversion rates selectable from 1/minute to 500 kHz. Long duration of 42 days for data logging function. Automatic calibration of PC time base settings." A year or so ago, the prices of the components were as follows: PC-SCOPE software (executable only) $49.00 ANA150 board $119. PC-SCOPE (source code) $149.00 I found that the package was easy to install, worked as advertised and was, in my opinion, well worth the rather low price. Warren F. Davis ================================================ Davis Associates, Inc. 43 Holden Road West Newton, MA 02165 U.S.A. Tel: 617-244-1450 FAX: 617-964-4917 Visit our web site at: http://www.davis-inc.com ================================================