The following operators can be used to better focus your queries.
( ) , AND, OR, NOT, W/#
? single char wildcard, not at start
* multi char wildcard, not at start
(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*
This guide provides a more detailed description of the syntax that is supported along with examples.
This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.
Concept Search - What can I type?
For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.
Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.
Write equalizers are digital filters used to alter phase and frequency characteristics of recorded data on disk, tape and optical storage products.
English (United States)
This text was extracted from a PDF file.
100% of the total text.
Page 1 of 1
Programmable Write Equalizer
Write equalizers are digital filters used to alter phase and frequency
characteristics of recorded data on disk, tape and optical storage products.
Three-term write equalizers alter the write data output based upon the
present data bit (Yn), the last data bit (Yn-1), and the next data bit (Yn+1) to be
written. This incoming pattern determines the output write data pulses to be
The output data bit cell is divided into two half-cells, ø1 and /2 . At the
beginning of each half-cell, the logic must produce a pulse in the opposite
direction of the last pulse (Toggle), or in the same polarity (same). This circuit
uses two eight bit registers and two eight-to-one multiplexers to make this toggle
logic completely flexible under microcode control for both half-cells /1 and ø2 .
This circuit can, for example, write 3480 data pulses and 441 or 423 pulses. This
allows the same circuit to be backward compatible with existing products under
Any 3-term write equalizer can be implemented with this circuit. This
includes 3480 code and follow ons, and the write equalizer is easily modified "on
the fly" by the microprocessor. This allows the circuit to write tapes of different
formats under microcode control.