A Blog About Random Computer Subjects
I completed all the wiring for the Nibbler and of course, it doesn’t work. I was expecting that. In fact, if it worked correctly, I would have suspected something was up. Here’s what the front and wired side look like so far: The first thing I did was beep the wires, or rather, check continuity. … Read moreNibbler – Wiring Complete
I wired up all the VCC and GND pins on all discrete components, as well as the chips. Here’s what the bottom of the board looks like so far: I’m not spending a ton of engineering time on this circuit. So I didn’t do my due diligence and compute how much power each chip used … Read moreNibbler – Power Wires Complete
I finished arranging and soldering the wire wrap sockets to the board. I also wired up the VCC and GND buses. Here’s a photo of the latest version: The bus bar running down the side is ground, and the one running across the top is VCC (+5v). I have mounted most of the discrete components. … Read moreNibbler – Ready to Wire
The circuit for the 4-bit computer called Nibbler is simple. It only has 17 ICs, which means it can be easily assembled on a prototype board with wirewrap sockets. Or so I thought. First, it’s tough to find the variety of wire wrap sockets needed. Amazon actually sells a few, but you have to watch … Read moreNibbler – Getting the parts organized
Introduction I recently (like a few months ago) stumbled onto an article about the Nibbler. It’s a 4-bit computer built out of discrete logic. There is no microprocessor, so this is lower level than slapping together a minimal system with a Z-80. Here’s the original article if you want to see what I’m attempting: Nibbler … Read moreA 4-bit Computer
My latest hobby is to learn VHDL and apply to the Mimas V2 FPGA board. As with any language, reading about the language is all well and good, but attempting a real application is where the rubber hits the road. I read through several tutorials and some introduction material to familiarize myself with some of … Read moreVHDL – Shift Register
After finishing the beginner’s guide for the Mimas V2 Development Board, I decided to try my hand at a circuit that I previously built with the GAL16V8 chip. I already had the PDS file for the BCD to Hexadecimal LED display, so I decided to try that. First, I needed to figure out what I … Read moreFPGA – Hex LED Display
I recently purchased an FPGA development board. Specifically, the Mimas V2 Spartan 6 board. There’s a really good introduction to this board which you can access by clicking here. The board looks like this: You can connect a micro-USB to USB cable to this board and program it from your PC. Plus, the power from … Read moreThe FPGA
In previous blog posts, I showed how the GAL16V8 operated and how to program it (see here and here). In this blog post, I’m going to discuss the differences between the 16V8 and the 22V10. Here’s the specification sheet for the GAL22V10: Lattice GAL22V10 Specifications. On first inspection, both devices look identical, except for the … Read moreProgramming the GAL22V10
When I wrote my blog post about building an ALU from an EPROM, I intended to use an EPROM from my old bag of parts. Unfortunately, none of my old UV erasable PROMs worked with the programmer. I’m assuming they are old and not usable. So I purchased a pair of 28C64’s from Jameco Electronics. … Read moreBuilding an ALU From EPROM – The Circuit