Soviet КР565РУ5Д1 (32k x 1bit) DRAM replacement?

[clueless_engineer (Brett)]

Hi,

Any suggestions on a Western replacement for this DRAM? I have seen Mostek MK4332D-3, but were there any other types produced ... that might be cheaper?

The machine I'm working on has 32KBytes of RAM implemented using eight of these 16-pin chips - four seem to be faulty, pulling the data bus high (I removed one and that bit was no longer being pulled high).

Thanks

 

[seat safety switch]

MK4332 datasheet provides the following pinout:


It seems to be two 4116s stacked together (which I guess is why there's separate RAS/CAS lines?)

 

[RetroAND]

Also the 4132, which was the actual stacked 4116. The 4332 incorporated the two dices in the same package, but they were replaced quickly by the 4164-based 4532.
I don't expect the cost to be cheaper. So better you find a seller from Eastern Europe and find the Soviet equivalent. This is the cheap solution. By the way, I would be interested in acquiring memories of this kind as the Datamaster carries lots of them.

By the way, what machine are you working with? You made me curious...

 

[jplr]

The Russian IC has 16 pins, not 18. Am I missing something?

565РУ5

565РУ5, К565РУ5Б, К565РУ5В, К565РУ5Г, К565РУ5Д, 565РУ5В, 565РУ5Г. Параметры, документация PDF (даташит), технические условия, описание.

elcomps.com

 

[RetroAND]

Then if it really is 32Kb it might not have a Western equivalent. 4116, 4132 and 4332 have multiple supply pins. If the Soviet made this chip with a single power pin they might have reused one of them for the additional address signal. That or this is a 4532 which is pin-compatible with the 4164.

 

[shattered]

It's likely a 4164 clone that failed QC and was binned as a 32K chip -- https://zxbyte.ru/byte_ram.htm

 

[seat safety switch]

The Russian IC has 16 pins, not 18. Am I missing something?

View attachment 1297175

565РУ5

565РУ5, К565РУ5Б, К565РУ5В, К565РУ5Г, К565РУ5Д, 565РУ5В, 565РУ5Г. Параметры, документация PDF (даташит), технические условия, описание.

elcomps.com

Good catch. I didn't even look at the picture!

That looks very much like a 4164 pinout...

 

[clueless_engineer (Brett)]

Yep, thanks everyone! The consensus seems to be ... just use a 64kbit chip with A7 (pin 9) pulled high.

From the data sheet:

Примечание: При адресации строк и столбцов для К565РУ5Д1 А7=1
Note: When addressing rows and columns for K565RU5D1 A7=1

 

[Eudimorphodon]

For a brief period in the late 70’s they were selling 8K “4108” chips that were just 4116s with one bad bank, and what was particularly amusing is the datasheet specified based on the suffix stamped on the chip if you held A6 up or down. (IE, they sold them in two “flavors” differing only in markings depending on which side was bad, and you had to be sure to use them in matched sets.)

Supposedly they did the same thing with half-bad 4164s (it was widely rumored that the first “32k” Tandy Color Computers used them, for instance), but I haven’t seen an actual printed datasheet or chips so marked. Maybe it was a dirty little secret between OEMs?

 

[clueless_engineer (Brett)]

By the way, what machine are you working with? You made me curious...

This particular machine is called an УМПК-Р (UMPK-R) from Ukrainian SSR - it's a "serially produced" computer based on the DIY Радио-86РК (Radio-86RK). It came in 16KB or 32KB versions.

My work-in-progress translation of the manual is here - idea is that it'll help with troubleshooting other RK-based machines.

GitHub - 0ddjob/UMPK-R_Computer: Information about the Soviet Ukrainian computer

Information about the Soviet Ukrainian computer. Contribute to 0ddjob/UMPK-R_Computer development by creating an account on GitHub.

github.com

 

[jplr]

I wonder if there is a "dictionary" somewhere that gives the Western part number for a Russian IC?
I created a tentative list (probably mostly buggy) with "westernized" script. Please see the included CSV file.