Re: In search of bad 4164, 41256 DRAM

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Sat, 21 Sep 2019 08:12:42 +0200 Message-ID: <ca9b8056-a0fe-a694-393b-a92c1c8d13ee_at_laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 9/20/19 7:53 PM, Jeffrey Birt wrote:
> I have this working well now for 4164 and 41256 devices. When not testing all pins connected to the DUT are set to HI-Z and power +5V is disconnected. This was done so chips can be removed inserted with the Arduino powered.
> 
> I was thinking of adding some 100ohm resistors in the address and control signal path as a simple protection against short circuits in the DUT.

In the 264 series (C16/+4), Commodore used 68 ohm series resistors in 
the address lines. And that's with the DRAMs running at full speed. So 
you should be OK with 100 Ohm.

  Gerrit