Raffel, J. I. (Jack I.)

Scope and Contents

Project Whirlwind Memo M-2384. Master's Thesis Research Proposal on a Large Planar Switch for Register Selection in a Magnetic-core Memory. The purpose of this thesis is to evaluate a proposed selection scheme for a magnetic-core memory and to compare it with that presently used at the MIT Digital Computer Laboratory.

Scope and Contents MIT DIC 6889. Project Whirlwind Memo M-2736. A memory system in which the memory functions (remanence) and the selection function (nonlinearity) are performed in separate cores may have the following advantages over the present (coincident-current) system: 1) Much broader tolerances on core acceptability 2) Reduced noise out of the memory array 3) Larger signals out of memory 4) Shorter memory cycle time Some of the costs may be: 1) Two or three times as many cores required 2) More...

Scope and Contents Division 6 Memo M-3505. The coincident-current magnetic-core memory was suggested in 1949 by Jay W. Forrester as a reliable, random-access storage medium. Development of the first working memory of this type, for the Memory Test Computer at M.I.T., established conclusively the superiority of such a memory over competitive systems and paved the way for others to exploit the new device. Includes: magnetic memories, external selection, experimental results, memory criteria, design...

Scope and Contents

MIT DIC 6889. Project Whirlwind Memo M-2291. A scheme is outlined which eliminates roughly half the bias drivers used in present models of the magnetic matrix switch. It calls for an increase of about 50% in the number of wires passing through a core in the switch.

Scope and Contents

MIT DIC 6889. Project Whirlwind Memo M-2351. The difference between the minimum wanted output (a system ONE) and the maximum unwanted output (a system ZERO) is the same for a winding which threads the cores so that each half of the memory plane has a different polarity as it is for one in which all the outputs add.

Scope and Contents MIT DIC 6889. Project Whirlwind Memo M-2919. Two properties of the sensing winding used in the Whirlwind I and MTC core memories are common to a large class of winding configurations. These are: 1) maximum partial cancellation of core "noise" 2) no inductive coupling between drive and sense wires. A new winding is suggested to replace the present zig-zag geometry. This should prove easier to implement and preliminary tests on a plane containing both old and new sense windings indicate that...

Scope and Contents MIT DIC 6889. Project Whirlwind Memo M-2348. Criteria for design of switch cores to be used in a magnetic-matrix switch are established. Core loss is shown to depend only on the average value of net ampere-turns excitation if certain assumptions are made about memory requirements and switch construction. Temperature effects on core output are discussed, and the problem of heat dissipation is considered. Comparison of 2 ferrite and 1 metallic core materials show the latter superior, and...

Scope and Contents Project Whirlwind Report R-234. The practicability of the magnetic core as the basic storage element in a high-speed digital computer has been established with the installation and successful operation of the banks of core storage in the WWI computer. It has long been realized that the basic function of a memory system, storage and switching, can be performed in many different ways using cores. Some techniques for performing these functions, especially selection, are explored and analyzed in...