The electronic circuit described below can switch the clock signal of a Z80 CPU between 2 different sources. This can be used to make a turbo circuit in a Z80-based system. It was originally designed for use in MSX computers, but is probably suited for use in other systems as well. Its main advantage over similar circuits, is the ability to switch
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between totally independent clock sources. This description is provided for reference purposes only: I consider this circuit completely outdated (regardless of how well it works) because there would be much better ways to construct a Z80 turbo circuit these days. It`s just that it never was a priority for me to update this circuit using currently available parts/technology - I leave that to other interested parties. Also the hardware/software environment, and typical use cases, have changed significantly since this design was made. Which (IMHO) makes most reasons for upgrading a Z80-based system questionable. But there appear to be still some people interested in doing such upgrades, and I have no problem with providing info. This page was mirrored in other locations, but seems to have disappeared from the web recently (or hard to find). Therefore I decided to re-upload it. To make it clear: I have not built these circuits for a looonng time, and don`t plan to! Nor am I selling circuit boards, kits or parts. Or soldering these things into MSX computers. I just provide this info - enabling you to find out how it works, Do-It-Yourself, have someone else do it, or base an improved design on it. It cannot make an MSX run faster in all circumstances; that a Z80 inside the MSX is capable of running faster, does not imply that you can let it run faster, nor does it mean the rest of the computer will work faster as well. It was...
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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