2 Mbit magnetic bubble memory

An experimental 2 Mbit bubble memory unit containing thirty-two 64 kbit chips has been built and tested for the file memory in electronic switching systems. The memory unit has 5 ms average access time and 1.6 Mbit/sec data rate. The memory unit has been subjected to extensive functional and environmental tests for about 1 year to insure a practical file memory. Overall 8 Oe bias field margin ever the -10°C to 50°C temperature range is obtained. No resonance and no bias field margin drift were encountered under 5 to 55 cps and 5 G of vibration (G=980 cm/ sec²). Non-volatile storage at -40°C and 70°C were demonstrated. A read error rate of less than 9×10^-12/read was achieved. These results insure a practical use electronic switching system file memory.