The instrument features 500 Megasample/s 8-bit ADCs for each channel. Faster sample rates can be achieved by combining two or four channels, bringing the sample rate to a maximum of 1 GS/s on 2-channel models and 2 GS/s on 4-channel1 models. When ail available channels are used, the waveform acquisition memories consist of 25K data points per channel — on Models M and L respectively 100K and 2M. More acquisition memory — up to 4M on 2-channel L models and up to 8M on 4-channel L models — can be achieved by combining two or four channels (see Appendix A, "Acquisition Memories"). Four memories are available for temporary storage and four additional memories are available for waveform zooming and processing. The central processor is a Motorola microprocessor which performs computations and controls the oscilloscope's operation. All front-panel knobs and buttons are constantly monitored by the front-panel processor, and front-panel setups are rapidly reconfigured via the unit’s internal 16-bit bus. Data are quickly processed according to the selected front-panel setups, and are transferred to the display memory for direct waveform display or stored in the reference memories. The main microprocessor controls the unit's GPIB (IEEE-488) remote control port, as well as the RS-232-C port which is used to directly interface the oscilloscope to a digital plotter, printer, remote terminal or other low-speed device.