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Microprocessor based system for the development and emulation of programmable calculator control read only memory software

  • US 4,277,827 A
  • Filed: 01/02/1979
  • Issued: 07/07/1981
  • Est. Priority Date: 01/02/1979
  • Status: Expired due to Term
First Claim
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1. A system, used externally in conjunction with a programmable calculator containing an external control read only memory port and a control read only memory for generating instruction and clock signals, for emulating and developing control read only memory of said calculator, comprising:

  • (A) means for connection to an external control read only memory port of a programmable calculator for receiving said instruction and clock signals,(B) means for emulating an external control read only memory for said calculator coupled to said means for connection said means for emulating comprising;

    (1) interface controller means connectable to said port of said calculator for decoding instruction commands received from said calculator via said port for providing selected data via said port to said calculator for execution therein in response to said instruction commands; and

    (2) memory means, coupled to said controller means for providing to said controller means prestored data corresponding to a control read only memory program, in a sequence addressed by said controller means, said controller means including means for decoding said data from said memory means and for transmitting said data to said calculator via said port, whereby said control read only memory of said programmable calculator is being replaced by the memory means.

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