Transformer Read Only Storage
Encyclopedia
Transformer Read Only Storage called TROS in computer parlance is a method of creating a ROM
in the '60s and early '70s before solid state
memory devices were developed.
The idea of TROS was to create a Read Only Storage method to contain computer microcode
. There were several implementation methods used but one notable method used the same technology as core memory
that was the primary method of computer memory used during the same period. The specific method was called Core rope memory
which used a ferrite core with wires strung through the core like a standard core memory but in some cores one of the wires would be routed around the core itself. The routing of this wire determined the interpretation of a 1 or a 0 with 1 representing a wire that ran through the core and a zero representing a wire that looped around the core.
in main frame computers and also as microcode in intelligent controllers used to control sophisticated memory devices such as disk drives and tape drives. If there were a bug in the microcode it was possible to rework the memory by carefully rerouting the wire and thereby change the contents of memory.
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
in the '60s and early '70s before solid state
Solid state (electronics)
Solid-state electronics are those circuits or devices built entirely from solid materials and in which the electrons, or other charge carriers, are confined entirely within the solid material...
memory devices were developed.
Overview
Microcode
Microcode is a layer of hardware-level instructions and/or data structures involved in the implementation of higher level machine code instructions in many computers and other processors; it resides in special high-speed memory and translates machine instructions into sequences of detailed...
. There were several implementation methods used but one notable method used the same technology as core memory
Magnetic core memory
Magnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
that was the primary method of computer memory used during the same period. The specific method was called Core rope memory
Core rope memory
Core rope memory is a form of read-only memory for computers, first used by early NASA Mars probes and then in the Apollo Guidance Computer designed and programmed by the MIT Instrumentation Lab and built by Raytheon....
which used a ferrite core with wires strung through the core like a standard core memory but in some cores one of the wires would be routed around the core itself. The routing of this wire determined the interpretation of a 1 or a 0 with 1 representing a wire that ran through the core and a zero representing a wire that looped around the core.
Use
TROS memory was used as microcodeMicrocode
Microcode is a layer of hardware-level instructions and/or data structures involved in the implementation of higher level machine code instructions in many computers and other processors; it resides in special high-speed memory and translates machine instructions into sequences of detailed...
in main frame computers and also as microcode in intelligent controllers used to control sophisticated memory devices such as disk drives and tape drives. If there were a bug in the microcode it was possible to rework the memory by carefully rerouting the wire and thereby change the contents of memory.