Old Calculator Web Museum Documentation Archive
Friden "Four Counter" EC-130 Version 1 MDD (Master Design Documentation) Computer Printout, 1964
Early Friden EC-130 "Four Counter" MDD Computer Printout (1964)
This document is an internal Friden "Master Design Document" (MDD) that
describes the entire design of the calculator. It documents the signals
used, logic gate connectivity, and component connectivity and location
on the circuit boards for the AD (Four Counter, Serial number <8501) version
of the Friden EC-130 electronic calculator. This document
has not been decoded as yet in terms of how to read/interpret the content.
It is presented here in hopes that it will solicit discussion and perhaps lead
to the document being decoded. If you have comments or questions
about this document, please contact the curator of the museum. The
first section (glossary) appears to define all of the signal names
used in the machine. The second section (logic schematic), appears to
define the machine in terms of its logic elements (gates, inverters, flip
flops), and how the logic elements are interconnected. The last
section (construction file) appears to define the actual component netlist
and cicuit board component layout.
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