A DRAM tester is actually nothing special, but this one is. This device can also be used to test DRAMs of type 4116. Why is this so special? DRAMs of type 4116 require a voltage of -5V and +12! My Polar 320 cannot test this type.

DRAMs

• 41:000
• 4116 (16,384 x 1 bit - 2,048 byte - 2 KB)
• 4164 (64,536 x 1 bit - 8,192 byte - 8 KB)

The test duration is about 17 seconds for a 4116 DRAM and 68 seconds for a 4164 DRAM.

For operation you need a 9V power supply with (+) in the center! Before you test anything, please check the correct polarity on the 9V connector and the correct voltages on the two sockets. Never test a 4164 RAM in a 4116 socket because it is likely to be fried.

I find this DRAM tester ingenious because it is so simple, plug in the DRAM and press the button, wait a bit and you're done. Today (02/08/2023) I just checked 32x 4116 DRAMs for a S-100 memory card for my North Star Horizon.