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Author Topic: Using DRAM memory (Read 1071 times)

Offline Bagpuss22

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Using DRAM memory
« on: 2015.April.09. 13:51:07 »
This is not an Enterprise issue as such but I wanted some advice on using DRAM.

I have a synth that has the facility to upgrade the sample memory with a card using
256k x 1bit DRAM, 12 of them.  These IC's have a single write enable line (W) and
separate input and out bits (D) and (Q) which are tied together.

That seems simple enough.

I want to create a memory card that uses 256k x 4bits, 3 of them.  These IC's have a
single write enable (WE) AND an output enable (OE) and the 4 bits are I/O ports.

So again this seems easy enough apart from the usage of the WE and OE.  I have a single
write enable (W) coming in so my question is, does anyone have experience using these and
how do the (WE) and (OE) get derived from a single (W)?

My assumption so far is that the (W) will go to the (WE).

Russ

Offline Bagpuss22

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Re: Using DRAM memory
« Reply #1 on: 2015.April.09. 14:22:49 »
I have just had a look at the schematics of the ZX Spectrum+3, as this uses
64k x 4bit and this seems to tie the Output Enable (OE) to ground......

Offline Zozosoft

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Re: Using DRAM memory
« Reply #2 on: 2015.April.09. 14:36:27 »
I have just had a look at the schematics of the ZX Spectrum+3, as this uses
64k x 4bit and this seems to tie the Output Enable (OE) to ground......
And look the Enterprise Modell 911 :-)
It is same.
12271-0
« Last Edit: 2015.April.09. 14:50:33 by Zozosoft »

Offline Bagpuss22

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Re: Using DRAM memory
« Reply #3 on: 2015.April.09. 15:23:09 »
Thanks for that confirmation.

Will see how it goes.

Offline ergoGnomik

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Re: Using DRAM memory
« Reply #4 on: 2015.April.09. 18:47:04 »
What about the refreshing scheme (9 bits vs 8 bits)?

Offline Bagpuss22

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Re: Using DRAM memory
« Reply #5 on: 2015.April.15. 00:17:15 »
What about the refreshing scheme (9 bits vs 8 bits)?


Good point....

Just thinking out loud then, would it be better to use Static RAM?