THE MODEL 175 The Model 175, Arbitrary Waveform Generator (Arb), generates any waveform that can be expressed as a function of time. The working Random Access Memory (RAM) has four sets of 256 addresses and each address accepts an 8 bit word. This corresponds to a 1024 (time) by 255 (amplitude) matrix in which to draw waveforms. These storage addresses can be manually loaded by front panel controls or remotely loaded via the GPIB interface. The stored waveform, or any portion thereof, then can be generated at selectable clock rates and amplitudes. In addition to the four working Random Access Memories (RAMs), four optional Programmable Read Only Memories (PROMs) allow the same capacity for permanent waveform storage. Sine, triangle, square and ramp waveforms are always available. Operation can be continuous or triggered. Triggering can be for a preset number of cycles or the number of cycles triggered can be monitored and displayed. Start and stop addresses are selectable for partial waveform output. At low frequencies, point-to-point smoothing can be selected to minimize digital step size. Output may be held at any level, or amplitude and offset can be slowly ramped to zero when a ramp to zero command is given. Front panel operation is by keyboard and display which gives immediate verification of parameter and value in memory. The Model 175 is fully compatible with the requirements of IEEE Standard 488-1975 for integration into a General Purpose Interface Bus (GPIB).