11 Nov
2008
11 Nov
'08
6:11 a.m.
It had both core and rope
http://en.wikipedia.org/wiki/Core_rope_memory
Rod
-----Original Message-----
From: cctech-bounces at classiccmp.org
[mailto:cctech-bounces at classiccmp.org] On Behalf Of Chuck Guzis
Sent: 11 November 2008 07:40
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: Who wants to help read a Saturn V core stack?
On 10 Nov 2008 at 22:37, dwight elvey wrote:
Reading shouldn't be too difficult. Outputs could
be recorded by a
digital scope. The rise times of the address and inhibit lines are
mostly to be slow enough that it doesn't cause the sense amplifier to
trip on the coupling in the selected address line.
Other addresses are protected by the matching signal on the inhibit
line. Any reasonably slow ramp would work since one is using a scope
to record and not a sense amp.
Putting to bed the idea of the "core rope" program store, the 1964
document on the launch computer is pretty clear that this is ordinary
read-write core storing the program:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730063841_19730
63841.pdf
In particular, item 2-37 begins "Reading a ferrite-core memory destroys
the information in the memory." It then goes on to describe the restore
part of a read operation. No mention of "core rope" is made. The
document, all 200-some pages contains a great deal of detail on the
computer, including memory operation and organization.
Cheers,
Chuck