Test results on an experimental crosstie random access memory (CRAM)

Results of tests on experimental CRAM chips are presented. The chips had twenty-eight leads and were mounted on leadless chip carriers. Each chip contained four memory columns plus a reference column. There were 64 bits in each column of 81-19 Ni-Fe: The next four levels were Si3N4, Al-Cu, Si3N4and Al-Cu. These materials were used to keep the experimental memory compatible with integrated circuit materials, since the CRAM must eventually be integrated with decoders and drivers on the chip. The CRAM could be written with coincident current pulses as short as 20 nsec. Non-destructive reading was accomplished in 800 nsec and this can be improved considerably with better design. Several obvious improvements are pointed out in the paper.