FPGA VAX update, now DIY TTL computers - test-drb@ccmp.vtda.org

3 Nov 2005

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Subject: Re: FPGA VAX update, now DIY TTL computers
   From: "Chuck Guzis" <cclist at sydex.com>
   Date: Thu, 03 Nov 2005 15:22:03 -0800
     To: cctalk at classiccmp.org

On 11/3/2005 at 7:53 PM ard at p850ug1.demon.co.uk wrote:

 There was a hrrible thing called fake parity
memory. It stored 8 bits and 
calaculted the parity bit on a read (ignored the incoming parity bit on a 
write) to keep the memory controller happy. Of course you can't store 9 
bits in that type of device. 
Of course you can, as long as the bits you're storing agree with the parity
of the 8 bits...

:) 
If you ask me the real horror of parity memory is it only tells you disaster
happend just as your about to crash.  It offers little to system reliability
and data integrity that real ECC can provide.  Like Tim O' said years ago
it's all a plot to sell more ram.

Allison