14 Mar
2021
14 Mar
'21
8:20 a.m.
On Mar 13, 2021, at 1:34 PM, Joshua Rice via cctalk
<cctalk at classiccmp.org> wrote:
The key component of core rope memory (and X1 ROM) is square-loop cores, like the cores
used in conventional read/write core memory.
There is another kind of core ROM where the cores are simply transformer cores. Since you
mentioned a "selection" coil, chances are that's what we're dealing with
here.
Brent Hilpert has a great writeup on a number of the technologies used.
http://madrona.ca/e/corerope/index.html
paul
Very interesting looking. I can't quite make
out what is going on in that rectangular area where all the wires terminate, labeled 0-15
and A-R. Are there diodes there? Anything on the other side of that board?
Nothing but traces on the other side, though you?re right on them being diodes.
The large cores with all the wires are
remisniscent of core rope ROM. If so, I wonder if it's AGC (Lincoln Labs) style,
EL-X1 style, or a scheme different from either of those two.
It?s definitely some form of core rope ROM.
Interestingly, the ferrite rings are built in pairs, with a "selection" coil
wrapped around both, joining them. Therefore (i assume, i?m really no expert) they?ll be a
positive pulse induced when passing through one coil, but a negative pulse when passed
through the opposite coil. This probably helps in differentiating beween a 0, a 1, or a
NULL state (ie 0v).
I have no idea if that correlates with any particular format of Core Rope, but as far as
my eyes can tell, that? how the core rope is woven and functions.