Memory Tester for DRAM Chips with Arduino Mega 2560 (EN)

After my memory tester for SRAMs worked as intended, I went on with my second Arduino shield for testing DRAMs. With this shield the following DRAMs can be tested:

4k x 1: 2104A, 4015, 4027, 7027
16k x 1: 4116, 2117, 6116, 8116, 416, 2116, 3716, U256
16k x 1: 2118
16k x 4: 4416, 2620
32k x 1: 3732H (4532-L4) und 3732L (4532-L3)
64k x 1: 4164, 2600, K565RU5, 8264, 3764
64k x 4: 4464, 41464, 50464
256k x 1: 41256, 53256, 81256, MT1259 883C
256k x 4: 44256, 514256
1024k x 1: 41024, 411000

Theoretically, all other DRAMs that have an identical pin assignments should also be able to be tested. The following video shows how the tester works with a faulty 4116.

Failed memory test of a 4116

To test 4116 chips, the shield has a pin header for the voltages + 5V, + 12V and -5V. In the video, a converted ATX power supply is used, which supplies these voltages stable.

Memory Tester for SRAM Chips with Arduino Mega 2560 (EN)

The revised version of my memory tester has been finished. The following SRAMs can be tested:

1k x 1: 2102
1k x 4: 2114, 2148, 2149, 5114, 6514, C214, U224
1k x 4: 6550
1k x 8: 4118, 4801
2k x 8: 2016, 4016, 4802, 4812, 6116, 6512
8k x 8: 2064, 2464, 6264, 2465
32k x 8: 20256, 61256, 62256, 71256

Theoretically, all other SRAMs that have an identical pin assignments should also be able to be tested. The following video shows how the tester works with a healthy 2102.

Successful memory test of a 2102

The following three videos show tests of 6550 chips. The first chip is healthy, the second returns the value „0000“ (= 0) for the test vector „0101“ (= 5) and the third chip returns the value „0001“ (= 1) for the test vector „0000“ (= 0) ).

Successful memory test of a 6550
Failed memory test of a 6550 (Bit permanently „0“)
Failed memory test of a 6550 (Bit permanently „1“)

As a bonus, a CRC32 can be displayed on the contents of type 2716, 2732, 2764, 27128, 27256 and 27512 EPROMs. This can be compared to an existing ROM image to see if the ROM content is identical.

Basically, the tester is already fully functional. I would like to make the power supply switchable, so that a chip can not be destroyed if it is inserted incorrectly. The board design is already done, but it will take some time before I will have the new version finished.

SRAM Tester rev.3

Update 30.8.2019:

The new version of the DRAM and SRAM tester is now ready. With the help of a MOSFET, the supply voltage is only switched on during the test. Thus, a chip with the wrong switch position may not be destroyed when inserting.