FPGA VAX update, now DIY TTL computers

woodelf bfranchuk at jetnet.ab.ca
Thu Nov 3 13:29:16 CST 2005


a.carlini at ntlworld.com wrote:

>There was a spate of "fake parity" memory around some time in
>the 90s. Quite why it was cheaper to add a chip that always
>supplied "correct" parity rather than simply using additional
>memory was something that I never understood. But if you
>end up with one these "fake parity" memories it may well
>cause your 9-bit machine some issues!!
>
>  
>
Well for my 9 bit machine, I am using 16k x 1 and 16k x 4 static ram 
chips to give me
64kb of memory out of  256kb of  total ram. As far as I know I the fake 
parity chips
were dynamic ram.  I hope to have 16k of ram for the OS and 48k for user 
programs.
However the first goal is to finish the hardware design and debug it for 
me.This is turning
into a wider 6800 style processer, but still a small system.

>Antonio
>  
>




More information about the cctech mailing list