Re: CBM-II solderless memory expansion

From: Jim Brain <brain_at_jbrain.com>
Date: Thu, 19 Apr 2018 18:06:11 -0500
Message-ID: <eed8ea47-a3c9-7106-b4b1-7cd7ee299f28@jbrain.com>
On 4/19/2018 3:48 PM, Mia Magnusson wrote:
> Den Tue, 17 Apr 2018 12:22:41 +0200 skrev Michał Pleban
> <lists@michau.name>:
>
> Nice!
>
> Btw I've noticed that availability and price of those old-style sram's
> have varied quite a bit during the last years.
>
> When you already have buffers for all adress lines and most control
> lines, maybe it would be a good idea to add something for the rest of
> the lines, and choose all components so it would be possible to fit a
> 3.3V SRAM (assuming a 3.3V regulator somewhere).
>
> Or maybe this isn't any good idea :)
>
I think it's a fine idea, and one I use a lot.  However, most newer SRAM 
is SMT, 3V3 or not.  If you're going to move to SMT, I would recommend 
putting all the logic to a CPLD (Xilinx XC95000xl series are 3v3 units 
with 5V tolerance when powered).

But, if one wants to stay through hole, I think it is still possible (I 
think you cna buy LVX/LVC TTL in DIP form that are 5V tolerant
Received on 2018-04-20 02:00:02

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