A Programmable CRT Display Scheme for Memory Output

This paper describes a novel scheme for the X-Y display of memory address versus contents with facilities to expand any region of interest (ROI) in the memory and to generate a marker corresponding to any selected address. Instead of using a digital-to-analog converter (DAC) for the x axis, a fixed-amplitude ramp is generated corresponding to user-selected addresses for the starting and completion of the scan over the desired segment of the memory. The CRT display is blanked for the region outside the selected range of addresses and intensified at the marker location. The scheme has been successfully used to obtain the X-Y display of the contents of selected regions of a memory, ranging from a minimum of 100 words to a maximum of 2000 words.