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Old 01 May 2012, 00:26   #2487
Schoenfeld
electricky.
 
Join Date: Jun 2010
Location: out in the wild
Posts: 1,243
Quote:
Originally Posted by alenppc View Post
Hi Jens,

I just emailed Vesalia to order the 1231. What a beautiful board! Made me dust off the good old A1200.

I am curious about a few things.

Where did you get the 030 cpus from? As I understand it, they are no longer manufactured so these must be old/unsold stock?
The CPUs were Vesalia's stock.

Quote:
Originally Posted by alenppc View Post
Why did you clock the CPU at 42 Mhz?
That was not a decision based on the CPUs, but based on memory speed. The SD-Rams I use are Winbond 200MHz types. They can deliver data within 48ns after row-open. This can be achieved by running memory clock at 83.325MHz, which gives 12ns per clock cycle. Running the CPU at half of the memory clock is the evident solution.

Quote:
Originally Posted by alenppc View Post
Is the synchronization with the main board the reason? If I remember correctly, the various M-tec cards used that frequency by mutliplying the A1200 motherboard clock.
I did that on ACA1230, but the ACA1231 is fully async. You can run it at almost any clock speed.

Jens
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