A3000D zip ram speed

[SpeedGeek]

The revision G Ramsey in the A4000 can be set for 'skip mode' which uses four clock cycles instead of five for each access, which provides faster memory performance and you generally need 60nSec memory for that.

Can't do that on the rev D Ramsey in the A3000 though.

For Ramsey Rev. D you simply change the Ramsey speed jumper J851. This does exactly the same as the skip mode.

[SpeedGeek]

Interesting point.  That actually controls the DRAM refresh timing, so moving J851 in that way will change refresh time from 9.5µSec to 6.1µSec.  Though there are still 5 clock cycles per memory access, and of course the clock speed remains the same.

Would be good to see the benchmark result of J851 in either position to see the effect.

I just released an updated version of RamseyConfig. You can use it to change the refresh mode but the skip mode is not supported:

http://www.amiga.org/forums/showthread.php?t=69397