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DRAMARDUINO - Dram tester with Arduino

Posted: Sat Oct 15, 2016 2:30 pm
by iss
Hi all!

Below you can see all details of my 2-hours 2-dollar project 'DramArduino'.
It's simple and very handy DRAM chip tester. It works with 4164 and 41256 IC's.
Testing is not too fast but acceptable - 4 different passes are performed in about 80 seconds total.
Results are 100% reliable only if the test FAILS - you can throw away the chip without fear.
If the test passes, this doesn't certainly mean that it will work in Oric, because as you know Oric's are very 'sensitive' to DRAM.
Actually this was my goal exactly - to sort out the working chips from about 200 before I'm get bored :).

Working with the tool is easy: place the chip in the ZIF socket, press small reset button, wait until GREEN LED blinks,
if it remains permanently on - chip is OK, if the chip is bad - RED LED lights.
If USB is connected, status is reported in your serial console. This helped me to detect some 'lazy' chips - they failed in
different, on every next test, growing addresses but when they become 'hot' test passes always.
IIRC such fail to boot Oric was reported somewhere in this forum...

Attached are 'schematic', source code and pictures - do with them what you want :).
(1.24 KiB) Downloaded 1447 times

Re: DRAMARDUINO - Dram tester with Arduino

Posted: Wed Jan 16, 2019 1:36 am
by Voyageur
Hi Iss,
Thank you for sharing the DramTester.
I've made one and it works !
I just controlled some 4164 and it is a good and not so long test :)
If you agree, I will show this Arduino shield on flag_fr CEO forum.
Have a good day !

Re: DRAMARDUINO - Dram tester with Arduino

Posted: Wed Jan 16, 2019 8:35 am
by iss
Hello, Voyageur!
I'm very glad that you liked this little tool and I'll be really happy if you share it on CEO forum.

Re: DRAMARDUINO - Dram tester with Arduino

Posted: Sun Mar 10, 2019 7:08 pm
by witchy
Hi Iss,

This was timed beautifully, for an upcoming 'Japanese Computing' exhibition at the Centre For Computing History in Cambridge I was testing my Sanyo MBC555 and the CGA card in there has 8x41256 chips on board. I built the tester on a breadboard and it works perfectly, thanks! Unfortunately it passed all 8 so the fault I have is elsewhere on the board.