On several occasions, Acorn`s initial specifications for a new machine and the final product have differed considerably in the features they provide. For example, the Risc PC`s motherboard SCSI controller and Phoebe`s ultra-fast scratch memory were consigned to history before ever seeing the light of day. These were mainly as a result of cost-cutting measures on Acorn`s part when the
Click here to download the full size of the above Circuit.
production cost of the final system was totted up. Another such casualty was the 16 bit sound system in the Risc PC, which was dropped on initial release to save a few pounds of parts. Acorn later realised that in the quantities they were dealing with, the cost of parts was tiny, so reintroduced this feature to motherboards that were shipped with RISC OS 3. 6 or 3. 7, but this left thousands of machines out there with the old system. Since the systems are different to access, software started to appear (such as PC Pro) that would not produce sound on the earlier machines. As the software to drive 16 bit sound is included in RISC OS 3. 6 or later, all that is required is the sound hardware. As the cost of parts is apparently so small, would it be possible to build a DIY 16 bit sound upgrade Commercial cards are available, so it must be possible, so I set out to find out. The 16 bit sound system in a Risc PC gives a sound output in digital format, which has to be fed to a DAC (Digital to Analogue Converter) to produce audio. Acorn`s costcutting measures meant this DAC and its associated clock were not present on early motherboards, so this is what we have to provide. The digital sound output arrives on the header LK8 directly from the VIDC chip in I ²S format. This is a standard devised by Philips for interconnecting digital audio components in CD players, DAT drives and so on. It is a serial output, where the 32 bits of...
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.....
characters left: