Who wants to help read a Saturn V core stack?

[Eric Smith]

Chuck Guzis wrote:
> Did some of the S/360 machines use ferrite ROM for their control 
> stores?  360/40 perhaps?  I believe some also used capacitive ROM 
> (360/30?).

The three ROS (Read Only Storage) technologies developed for the 
original System/360 processors were:

CCROS - Card Capacitor Read Only Storage - used etched metalized IBM 
cards, either paper or mylar.  Programmed using a normal card punch. 
Used in 360/30.  750 ns cycle time.

BCROS - Balanced Capacitor Read Only Storage - similar but used two 
capacitors per bit for better SNR and higher speed, and did not use a 
normal card punch.  Used in 360/65, with 90 ns access time and 200 ns 
cycle time.

TROS - Transformer Read Only Storage - similar in operation to core rope 
memory.  Used mylar film tapes with metalization that either passed 
between or around square holes for each of the transformer cores.  Used 
in 360/20 and 360/40.  240 ns access time, 625 ns cycle time.  Based on 
T.L. Dimond's "Dimond ring" transformer read-only storage first 
described in 1951.

See:

"No. 5 Crossbar AMA Translator," T. L. Dimond, Bell Laboratories Record 
Volume 29 Number 2 pp.62-68, February 1951

"Card Capacitor - A Semipermanent, Read Only Memory", H.R. Foglia, W.L. 
McDermid, H.E. Petersen, IBM Journal of Research and Development, Volume 
5 Issue 1 pp. 67-68, January 1961

"Printed Cards for the Card Capacitor Memory", J.W. Haskell, IBM Journal 
of Research and Development, Volume 6 Issue 4 pp. 462-463, October 1962

"The Design of Transformer (Dimond Ring) Read Only Stores", D.M. Taub, 
B.W. Kington, IBM Journal of Research and Development, Volume 8 Issue 4 
pp. 443-459, September 1964

"Design of a Printed Card Capacitor Read-Only Store", J.W. Haskell, IBM 
Journal of Research and Development, Volume 10 Issue 2 pp. 142-157, 
March 1966

"The 'Braid' Transformer Memory", W.H. Aldrich, R.L. Alonso, IEEE 
Transactions on Electronic Computers Volume 15 Issue 4 pp. 502-508, 
August 1966

"A Balanced Capacitor Read-Only Storage", S. A. Abbas, J. K. Ayling, C. 
E. Gifford, R. G. Gladu, T. C. Kwei, W. J. Taren, IBM Journal of 
Research and Development, Volume 12 Issue 4 pp. 307-317, July 1968

_IBM's 360 and Early 370 Systems_, E.W. Pugh, L.R. Johnson, J.H. Palmer, 
MIT Press 1991.