It is a high-performance digitizer that can be externally clocked at frequencies as high as 20 MHz and as low as a few kilohertz. The CompuScope 1220 can be used in applications in which clock frequency varies based on external inputs. It has two input channels, 12-bit vertical resolution, 20 Msamples/sec simultaneous sampling rate, 10-MHz bandwidth on most input ranges, external triggering, and external clocking. Input ranges as low as ±50 mV as well as ac/dc coupling and 50 ohms/1 ohms impedances are all software controlled. Dc accuracy is typically ±0.5% of full-scale input. The card can be equipped with up to 2 Gsamples of onboard memory. Up to eight cards can be combined as a Master/Slave system to provide up to 16 simultaneous input channels.