8Bit-Museum.de

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.

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) ).

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.

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.