[sdiy] How to use DRAM ?

[Anderson, Robert O]

Mnay years ago I made a digital bucket brigade delay reverb with 8 4116
dynamic ram chips.  After latching the read value and outputting to an DAC
(1408 = 0808) a new value ADC value was written into the previous location.
The whole thing was run by a few logic gates and a big binary counter (no
microprocessor).  I forgot what the refresh rate is for the 4116 but as long
as you read the capacitor cell within the refresh time the data was stored.
Some of the dynamic rams have banks and you can refresh a large number of
cells at once.

-----Original Message-----
From: Michael Buchstaller [mailto:buchi at takeonetech.de]
Sent: Wednesday, March 28, 2001 10:46 AM
To: synth-diy at node12b53.a2000.nl
Subject: [sdiy] How to use DRAM ?


as most other people, i have some 30- and 72-pin PC Memory
modules lying around. (4 MB...32 MB each)

Modern mainboards all wants DIMM´s, and everybody is throwing
out old 486 and early pentiums with such SIMM memory in them.

My idea is to use them in a sampling module or maybe a digital
delay.
But how does one access this RAM ? I have done simple things with
SRAM´s, but if i remember correctly, DRAM´s need some sort of
refreshing, and have to be re-written after reading.
How does one do this ? Has anybody used DRAM´s in a project
successfully? (without special SMD memory controllers of course)


-Michael Buchstaller