DRAM and SRAM testing

General discussion for retro computing
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Valdor
Posts: 49
Joined: Wed Nov 11, 2020 9:28 am

DRAM and SRAM testing

Post by Valdor »


@Damik - what programmer can test e.g. 4116? :)
I will buy - I will put it together - check - let me know (it will probably be possible to borrow it for fun at home :))
Just counting on fast - the amount for the components will be much lower than 120USD ...
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Doggeboy0A
Posts: 31
Joined: Fri Sep 24, 2021 11:26 am
Location: nowhere

DRAM and SRAM testing

Post by Doggeboy0A »


Each programmer / tester that can handle DRAM 2118 memories should test the 4116 with an appropriate adapter with a converter that gives the additional voltages that this system requires;)
You can also test 4116 in programmers / testers supporting memory 4416 in an adapter with a converter, banks of 4 pcs at a time
I'm good doggee
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Kilord
Posts: 29
Joined: Fri Sep 24, 2021 11:48 am
Location: Poland

DRAM and SRAM testing

Post by Kilord »


I am lazy and I want one device for this
I'm from Poland in Euro.
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BigAndSmallHills
Posts: 28
Joined: Fri Sep 24, 2021 12:02 pm
Location: Hills

DRAM and SRAM testing

Post by BigAndSmallHills »


I could have invested such money, but for something that I need at least once a week, not once in 2 years, and then only causes remorse as I look at it
Run for the hills, run for you life.
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ThisGuy01
Posts: 30
Joined: Fri Sep 24, 2021 11:55 am
Location: Middle of Europe

DRAM and SRAM testing

Post by ThisGuy01 »


Hi,
first at all sorry for writing in English. I am the curator of the 8bit-museum.de, a website that exists for 25 years now, and the developer of the memory tester you are talking about. In case you have any questions please feel free to ask me about it, but let me give you some information about it.
I started developing a tester for SRAMs for the Arduino about two years ago to test some memory chips from an EACA Video Genie and the Commodore PET, because the popular TL866 does not support these types. Shortly afterwards I developed a circuit board for 4116 DRAMs, also for the Arduino. Since several supply voltages are required, I added a power supply shortly afterwards.
However, it quickly became apparent that pretty much every computer manufacturer used its own RAM types, so that more RAM types were added, e.g. for the Sinclair Spectrum the half-defective 3732. The Arduino tester quickly became too impractical (too little space), so that I have now reached Rev.7 and Rev.8 over several versions (these two versions are almost identical, but the 8 series allows a ZIF32 socket (I also plan to develop these as 7 series = ZIF28 and 8 series = ZIF32).
I saw that the discussion arose about two things:
1. The accuracy of a memory tester
2. The cost of the boards
Pabbe has already posted a message from me about this. Accurate tests simply cannot be done with an 8 EUR chip. To test RAS / CAS timings exactly, 1-5ns triggering would be necessary, but the ATmega already needs almost 60ns for a command. With the above we would be in the GHz range, i.e. a two-layer board would no longer be sufficient and much more expensive components must be used. Without counting the development costs, we would reach several hundred EUR retail price, with the small quantities and development costs probably even well over 1000 EUR.
What would you have won then? You can then test 0.5% -1% more closely, i.e. in the event of an error, one more chip would be correcty recognized or a false positive would mean that one out of a hundred chips would be rejected. This is unnecessary for a hobbyist and makes no sense.
I write on my homepage that I "deliver the boards at cost price". Strictly speaking, this is not correct. If I actually include all (!) Costs (including the failed attempts with faulty designed boards, burned components or unsold boards), the boards would be much more expensive. So the price covers the current costs, i.e. I order a set of boards (I have to buy a minimum amount) and keep one for myself and sell the rest. The demand is not so high that every board always goes away. So I have to add a little buffer to avoid slipping too much, because then I could no longer finance the development. The time invested for the hardware (and we haven't talked about the software yet) is not included in the calculation (small fact: I currently have over 12 different versions of my memory tester which I strictly speaking do not need;))
In total, over 1000 hours have gone into the development of the tester and I am constantly improving it.
In the meantime, he can not only test SRAMs and DRAMs, but also identify EPROMs (very useful if the label is no longer readable, unfortunately only possible from 2732), he can identify (EP) ROM content (eg if you find an EPROM and do not know which software is on it), he can test several TTL / CMOS devices.
During the development, I tried to choose a middle way between cheap but still useful and accurate.
With all components it should be less than 50 EUR when you build it. With the documentation and the simplicity, you also have the option of programming something yourself based on it. I think that I have managed to find a good compromise.
I'm from Poland
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Smallbug
Posts: 27
Joined: Fri Sep 24, 2021 12:47 pm
Location: in the grass

DRAM and SRAM testing

Post by Smallbug »


Hi @slabbi and welcome on this forum. We don't mind if someone speak and write in English, so please feel free.
Regarding your tester, thank your for all details provided. They are very interesting and useful.
I'm just a small bug in grass.
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Yavin
Posts: 44
Joined: Wed Nov 18, 2020 7:57 am

DRAM and SRAM testing

Post by Yavin »


Maybe you have already noticed:
The "Old" version (Rev.8 ) will still be maintained, because it is simple to build and easy to program in case you want to create an own firmware for it.
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Catladyiscrazy
Posts: 32
Joined: Fri Sep 24, 2021 11:31 am
Location: Kitty Litter

DRAM and SRAM testing

Post by Catladyiscrazy »


this is truly PRO tool with a superb manual :)
Great job slabbi! I'm impressed.
Nothing here for now...
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Yavin
Posts: 44
Joined: Wed Nov 18, 2020 7:57 am

DRAM and SRAM testing

Post by Yavin »


You can buy a ready:
In fact, it only focuses on one type of memory.
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SanderoCaro
Posts: 24
Joined: Fri Sep 24, 2021 12:14 pm
Location: Car saloon

DRAM and SRAM testing

Post by SanderoCaro »


I watched - it is not worth attention (in my humble opinion of course :)).
The cost of the new version from Slabbi should not exceed PLN 270 for the whole ...
Sandero is good car :!:
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