Optimized Digital Message Entry Device (DMED).
ELECTRONIC COMMUNICATIONS INC ST PETERSBURG FLA
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The Optimized Digital Message Entry Device Program was an exploratory development program which resulted in the design and fabrication of two exploratory development models of a portable, two-way Digital Message Entry Device DMED. The DMED has been designed almost exclusively with complementary-metal-oxide-semiconductor CMOS MSI logic permitting five-day operation without changing or recharging the self-contained batteries. The device has two selectable bit rates, 150 and 600 bps two symbol sets, alphanumeric ASCII code and hexidecimal 4-bit binary code and two types of error control coding, a block iterated error detecting code for use with the alphanumeric symbol set and a Hamming 8,4 error correctingdetecting code which is used in conjunction with the hexidecimal symbol set. An internal adaptive audio FSK modem which permits the DMED to interface with the audio circuits of voiceband radios is a novel design implemented exclusively with CMOS logic and micropower FET amplifiers.
- Non-Radio Communications