The aim of this project was to create a front-end for Commodore 64 emulation using VICE. One of the primary problems with emulators (especially for machines from the `80s) is that there was no standard keyboard arrangement. In this project I took a broken Commodore 64 computer and replaced the motherboard with a PIC microcontroller based board whi
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ch interfaces the keyboard and both joystick ports (including ADC for the paddles) to a modern full-speed USB 2. 0 interface. The board is designed to fit inside the original Commodore 64`s `breadbox` case without requiring any modification to the original machine. In fact it is possible to fit this interface and at a later point remove it and replace it with the original motherboard (we have to preserve what we have!) The Commodore 64 keyboard is a straight-forward matrix keyboard with 8 columns and 8 rows giving a total of 64 keys. There is also an additional RESTORE key which (in the original machine) was wired to the CPU to act as a non-maskable interrupt key (or `break` key). In order to wire the keyboard up to the PIC controller I made a simple breakout adaptor for the keyboard connector (a 20-pin SIP female connector) and wired it to my PIC USB reference board (this board is actually a pin-compatible clone of the PICDEM FS USB board which I made myself): The reference board is useful because it acts as a `known working` USB implementation (this is so you know that only your software is wrong when it doesn`t work - otherwise debugging USB code can be a little tricky). Once connected I was able to test the keyboard and the method for connecting it to the PIC. I also decided to test the configuration of the keyboard matrix since this is very important for detecting `ghost keys` as you will see later in this article....
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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