As discussed last year in a Facebook group, this year’s holiday project is a ” Elektor Junior Computer” revival project. This means I will redesign. The Elektor Junior Computer was a simple based Microprocessor development board published in the s in the Dutch, German and later French and. Along the lines of the MOS Tech KIM, the Synertek SYM and Rockwell AIM, Elektor Electronics also published their SBC – The Junior.
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If not, then the wire link is in the wrong place. The power supply connections are:.
A multiplexed 4-digit, seven-segment display with only 12 pins. Press the reset button RST on the keyboard, the voltage between those two pins should now be approximately 0. The screen of a PC did not contain any character generation hardware, all signals and video formatting were generated by the video display card in the PC, or wlektor the CPU. These connections are labelled on the main board above the keyboard assembly.
This required an easy memory expansion, all of the decoding for the first 4 K is provided right on the KIM board, all you need to provide is 4 K more of RAM chips and some buffers.
His first assignment was helping define the peripheral ICs for the family, Motorolas engineers could run analog and digital simulations on an IBM mainframe computer. A bit is one piece of digital information or BInary digiT. The PIA is such a computfr and multi-functional device that we could quite easily write a whole book about it, but as far as this chapter is concerned, enough is enough.
Last, but by jjunior means least, is the control bus. The data bus consists of eight lines, but is bidirectional.
There are also two types of data: Computer memory that can retrieve stored data after a power supply has elektro turned off and it is an array of floating-gate elektr individually programmed by an electronic device that supplies higher voltages than those normally used in digital circuits.
This shows the Junior Computer is working properly. The display board of the Junior Computer can be mounted behind this once all the necessary holes have been made. When the information contained in RAM is to be saved for extended periods of time it is usually transferred to a more permanent form of data storage, cassette tape or floppy disc for example. Com;uter are two ways in which a program being run can be interrupted by means of the non-maskable interrupt NMI. It is often connected to a channel of the DMA controller.
Ten address lines are utilised by the memory, leaving six. The scope should have no trouble keeping the signals steady. They were also used to show the dialed telephone number compter operators during the cimputer from manual to automatic telephone dialing and they did not achieve widespread use until the advent of LEDs in the s.
If, however, you delay installation of the connector, provision must be made for the supply lines. Sixteen of these keys are used for entering data into the computer in hexadecimal code to be dealt with in chapter 2.
Using two pieces of wire, one on the top side of the hole and the other on the opposite side, if the bell sounds the plating is good. The switching state of the transistor is controlled by the voltage on the control gate of the transistor. As it is not likely to be needed just yet, the 64 pin expansion connector can be installed at a later date.
The controller is linked to the bus of the computer. The next stage is to connect the transformer Tr1 to the supply board, and via switch S1 and fuse F1 to the mains. Looking at it realistically, the hexadecimal keyboard as the standard input source, and the hexadecimal display as the output indication, are the simplest and least expensive methods of interacting with the computer.
If the project employ It took Elektuur some time and the potential user a lot of money to add a cassette interface tot the Junior design, Many users therefore bought the scalled musicprint cassette interface. The term PCB is used both for bare and assembled boards. See the included juniortapes.
Soldering mistakes are still the biggest headaches on home-built electronic equipment. USB interfaced stand alone Universal Programmer. Peddle, who would accompany the people on customer visits. Even an enclosure was not supplied, nor a power supply, microprocessor training development kits were not always produced by microprocessor manufacturers.
Where a system monitor program is used it is invariably stored in ROM. The data bus lines are arranged so that the first half four bits of the data is in IC4 and the second half is in IC5. Mattysek single-cycle voor junior-computer E. A further development of the diagram in figure 2: This is typical for start-stop communications, but the standard does not dictate a character format or bit order. Elektuur articles This is the list of dutch articles and books and paperware by Elektuur devoted to the CPU.
Therefore the limitation imposed by working with a number system with two as its base does not really pose a problem. A board designed in ; the sweeping curves in the traces are evidence of freehand design using adhesive tape. Download here the archive. The address bus is also used to select the various input or output devices needed by a particular program. Manufacturing circuits with PCBs is cheaper and faster than other wiring methods as components are mounted and wired with one single part.
The latter is a small board carrying the displays and is attached to the main board.
Along with the Zilog Z80, it sparked a series of projects that resulted in the computer revolution of the early s. The keyboard consists of 23 key-switches and 2 toggle switches. Elektog exhibits data remanence, but it is volatile in the conventional sense that data is eventually lost when the memory is not powered.
The electrical signals on the address and data buses are coded digital information. Soon after the ‘s introduction, MOS Technology was purchased outright by Commodore International, who continued to sell the microprocessor and licenses to other manu Some amount is also embedded in all modern appliances, toys.