TRANSISTOR COMPUTER SERIAL

Traditionally these used mercury as the medium and quartz crystals as the read and write transducers, or solid chunks of quartz crystal for the medium, but I’ve seen hobbyists implement delay line memory in air and water in recent years.Ī common thing I see in computers people build from the ground up, is that they attempt to use “modern” (i.e., post-1960) architectures, which assume the existence of random-access memory devices. Yes, these are slow, because the data is always circulating and you only have one moment in the whole cycle to read and/or write a particular bit.

I would think that the easiest to implement would be a delay line based memory. The first appearance of random access memory used CRTs that stored data as electrostatic charges on the faceplate of the tube, which greatly reduced the complexity of the circuitry required to access individual bits, but I think this is still a little outside the “scope” of hobbyist-accessible technologies. Even when random-access memory made its debut, the storage medium was the face of a CRT rather than individual storage cells. Discrete memory cells also need a lot of support circuitry to select a particular word, which is a bigger challenge than actually building the bit cells themselves.

TRANSISTOR COMPUTER SERIAL

Both magnetic core and transistor (either static flip-flops or dynamic cells) require separate discrete circuits for each bit, which is why many early computers used some sort of serial system such as a spinning drum, acoustic delay line, or moving tape (magnetic or punched paper). Memory has always been the tricky part, which is why the most important steps in the evolution of computers were in memory technology. Not as many solder joints, but very finicky circuitry, and wiring the core plane itself is probably as much work as wiring 640 transistors. Posted in Misc Hacks Tagged 4-bit, computer, discrete, discrete transistors, homebrew computer Post navigation He’s getting close to complete, if you don’t count soldering up the RAM, and already has a crude Larson scanner worked out. It’s a beautiful project, and something that has been working for months on. After looking at the problem, decided to look at how real demuxes were constructed, and eventually hit upon the correct way of doing things – inverters and ANDs. The project hasn’t been without its problems – the first design of the demux for the ROM access logic resulted in a jungle of wires, gates, and connections that couldn’t get a usable signal out of because of the limited gate fan-out of his gates.

The ALU is a 4-bit ripple-carry adder/subtractor, with plans for a comparison unit that will be responsible for JMP. This setup does have its advantages, though: the entire contents of memory can be dumped to a computer through a serial monitor. the RAM for this project is a bit of a hack – it’s an Arduino, but that’s only because doesn’t want to solder 640 transistors just yet. The ROM for the computer is just a bunch of 16 DIP switches and 128 diodes, giving this computer 128 bits of storage. is following in this hallowed tradition by building a four-bit computer, complete with CPU, RAM, and ROM from transistors, diodes, resistors, wire, and a lot of solder. Anyone reading this uses computers, and a few very cool people have built their own computer out of chips, is doing something even cooler over on hackaday.io: he’s building a computer from discrete transistors.īuilding a computer from individual components without chips isn’t something new – Minecraft players who aren’t into cheaty command blocks do it all the time, and there have been a few real-life builds that have rocked our socks.

Transistor computer