FR2501878A1 - Single stepping microprocessor for computer science training aid - uses programming card to load program and uses wired logic to stop clock for stepping of instructions - Google Patents

Abstract

The system uses a monobit microprocessor which has a keyboard with twenty three keys on which the instructions and addresses are inscribed in hexadecimal notation. The instructions are loaded directly into the memory by DMA. A program is loaded from a programming card and by pressing a program key the clock is stopped utilising wired logic. Subsequently, pressing a key loads the code for the first instruction into memory via a validation circuit. A subsequent key operation increments the clock address to permit writing to memory of all the instructions.

Description

DESCRIPTION
Domain:. automation of simple machines.

 didactic use for learning microcomputing.

 Previous devices use either powerful but expensive systems, or too crude systems that do not allow easy programming.

 The automatic device according to the invention makes it possible to avoid these drawbacks. In fact, it has few components and allows the execution of a maximum of 256 instructions with the input of a maximum of 48 inputs and 48 outputs.

It can be programmed directly from a 23-key keyboard on which instructions and addresses are written in hexadecimal.

The instructions are loaded directly into the memory by a DXL device (direct access to the memory), all the control being done by a tabled logic and not a microprocessor.

 Plate 1 describes the central unit which is conventional except for the logic of the clock CI7.

The program is loaded from the board 2 programming card.

Pressing the "PRO" key stops the clock and places the 14500 (ais) in a high impedance state.

Then pressing a key on the keyboard leads to the coding of the first instruction diit (by CI5) and the loading into memory CI3 by the validation circuit (CI2, CI3, CI4, CI5).

The next press causes loading into memory CI4. As release of the second press 019 causes the clock address to increment. We can thus write the entire instruction memory.

The device can be used effectively as an introduction to microcomputing;
To automate machines requiring a relatively simple program (no counting, no analog signal to be converted).

Claims (4)

 has a keyboard, memory and control logic.  l- Programmable automaton on single-bit microprocessor characterized in that it  2- Programmable controller according to claim 1 characterized in that the  keyboard has a set of keys that load instructions directly  in the memory.  3- Programmable controller according to claim 1 characterized in that the lo-  wired control panel blocks microprocessor clock and turns microprocessor on  in high impedance state.  4- programmable controller according to all of the preceding claims, characterized in that the keyboard assumes the incrementation of the address of