Hi Chuck and all, At 10:13 AM 4/24/99 -0700, you wrote: Yes, the wires went straight through. With a closed circuit (driver circuits) this is one turn anound the core. More turns would require less current, but would be much harder to make. Look at the picture at: http://www.wins.uva.nl/faculteit/museum/CoreMemory.html and imagine if the wires had to make loops around each core. It's the current that's important, the driver circuits would obviously require some voltage to deliver that current. Maybe someone could give the write currents for some example core, I haven't had a chance to read any spec's. Straght through, but usually the 45 deg. wires for less capacitive coupling to the driver wires. Remember that a "read" is a write + sense + possibly another write if the core was switched to switch it back. I don't know if this logic was taken care by the core subsystem or integrated into the CPU cycles, for any particular computer. -Dave