A mapping and memory chip hardware which provides symmetric reading/writing of horizontal and vertical lines
by D. L. Ostapko
This paper describes a mapping and memory chip hardware for enhancing the performance of an APA display. The approach describes a modification to the primary port of a quasi-two-ported memory. This modification allows several contiguous horizontal or vertical bits to be read or written in one cycle. The number of bits that can be stored is given by the number of memory chips. The hardware modifications can be on or off chip, and if on chip, the chip can still be used as a conventional memory chip. Simple modifications to the hardware will support different screen sizes.