Browse Prior Art Database

Software Tone Discrimination for an Intelligent Portable Computer Terminal

IP.com Disclosure Number: IPCOM000050151D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 4 page(s) / 65K

Publishing Venue

IBM

Related People

Voshell, TW: AUTHOR

Abstract

Disclosed is an intelligent portable computer terminal which eliminates hardware function of data tone discrimination (bit 0 tone versus bit 1 tone) by incorporating this function into system microprocessor operational code, thereby freeing the hardware system of this additional complexity. The implementation illustrated employs the same system microprocessor as the central computing and control element, the timing element, and the frequency discrimination element.

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Software Tone Discrimination for an Intelligent Portable Computer Terminal

Disclosed is an intelligent portable computer terminal which eliminates hardware function of data tone discrimination (bit 0 tone versus bit 1 tone) by incorporating this function into system microprocessor operational code, thereby freeing the hardware system of this additional complexity. The implementation illustrated employs the same system microprocessor as the central computing and control element, the timing element, and the frequency discrimination element.

Turning now to Fig. 1, a fairly standard terminal 10 is shown therein. For example, a microprocessor 11 is connected through address bus buffers 12 and a control and data bus 13, in a standard and conventional manner to both read- only store (ROS) 14 and random access memory (RAM) 15. Also connected to the control and data bus is display memory 16 which interacts within for example, an LED (light emitting diode) type, "moving sign board", type display. The control and data bus 13 is also connected to the keyboard 18 as by keyboard input/output logic 17 and to a parallel I/O logic chip 19, and to an analog section 20 for an input/output dynamic transducer 21.

By way of example only, the microprocessor may be a Z-80 employed as a general purpose computing element handling the typical duties of keyboard interpretation, LED display management, user prompting of desired entry, file building and maintenance, user error feedback and floating point calculations of certain keyed fields. Moreover, the microprocessor 11 also acts as a systems communications controller. This is caused by the microprocessor operating under instructions read from the ROS 14, for decoding and encoding zones used in communications up to, for example, 600 baud, asynchronously.

Typical ROS employed, may be, for example, a pair of 2732's;

RAM, eight 6514's; while the display 16 may be comprised of, for example, Litronix DL1416 (4) each of which display 4 ASCII characters providing 16 digits of user display. While these displays are byte addressable, they may be memory mapped through the system starting at any convenient location and addressable as discrete memory locations.

The keyboard is preferably a 40 key or more ASCII output device using low power CMOS technology, and may incorporate any convenient method of key encoding, such as scan/counter techniques. The keyboard 18 may be interfaced through the keyboard I/O 17 as a byte readable device through, for example, a National Semiconductor type 80C97 tri-state buffer. The parallel I/O may be an Intel 8255, as a typical example, which is a 24-bit I/O device.

The analog section 20, illustrated best in Fig. 2, comprises a plurality of operational amplifiers 22, 23, 24, 25 with the supporting circuitry with typical and exemplary values illustrated in the circuit diagram. The operational amplifiers handle input communication signals with an output section comprising a single ended, Cl...