different machines reasonable step rates?

[fyffe555]

Hi,

just finished building a new controller and a few questions popped up;

For some reason this new controller will not work with the two Thinkpads I've used previously. Had to plug in a 'real' pc . Here's some interesting numbers for the Maximum reasonable feed rate.

Thinkpad 300mhz; 45khz
Thinkpad P166; 22khz
p166 clone; 23khz
3.2Ghz P4; 22khz.....

Any ideas why the P4 is so slow?

Unless I can figure out why the laptop doesn't work with the new controller I'll have to get imaginative. Presently run motors very smoothly at quarter microstep and a high axis step rate/ acceleration. 22khz won't support that.

.

[balsaman]

many laptops parallel ports don't put out a full 5 volts. Some controllers need all 5 volts to work correctly.

Eric