How scarce (valuable) is core for the PDP-8?

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Tue Apr 20 15:46:24 1999

I wager teh wire used in the core is finer than #30, my bet is #40.


> I do not believe my engineering and math skills are adequate to design it,
> but given the specs, I sure could _build_ it. If anyone is considering
> this, please bore out the threads of the nut (if you use nuts) before
> determining the saturation current. It will minimize mechanical wear on
> the insulation. I may just go to the local fastener house and buy a box
> of #2 nuts and build a mat of this just to hang on the wall. ;-)

Skip all the fancy sillyness. All I need is s pulse generator that can
generate fast bidirectional pulses with currents to 1-2A and a scope.
from that I can tell what current saturates the core and what it's switch
thresholds are. actually a power supply abnd resistor and a switch will
do for the pulse generator, though it's more manual. the rest is easy.
The array will have to be tuned once built anyway but knowing what the X
and Y currents have to add to +/- 10% is enough to get it going. The
inhibit current will be the mirror of the half select current.

Oh, the same rig will be a good apprasial of the figure of merit for the
core.

Allison
Received on Tue Apr 20 1999 - 15:46:24 BST