When you’re dealing with computer logic, things can get very complicated very fast. This is especially true when it comes to address decoding. You can easily find yourself tangled in a messy web of AND, OR, NAND and NOR gates. And there’s a problem you can run into when stringing together a bunch of logic gates – propagation delay. It… Read more »
In my previous post, I mentioned how, while I’m following along with Ben Eater’s 6502-based homebrew computer project, I’m also making some revisions of my own. One of these is to use my own address decoding scheme. So far, things are working okay, but that post included a note about how I’m going to have to make some changes to… Read more »
Back in the first half of February, Ben Eater added parts 5 and 6 of his YouTube series on building a 6502-based homebrew computer. The enhancements he made gave the computer something it has been sorely lacking – memory. And the reason the computer needed memory was so it could have a stack. Up to that point, the code had… Read more »
Although it is possibly the slowest computer development programme in history, my Zolatron 64 6502-based homebrew design has made some progress. And this is largely due to the fine folks over at the 6502.org forum. Specifically, I have made changes to how I’m mapping the 64KB address space and the decoding I’m using to do that. I’ve been following along… Read more »
In my earlier post on address decoding logic, I mapped out a fairly simple way of dividing up the 64k address space for my 6502-based retro computer. But maybe it was too simple. There is one slight complication – easily fixed, but which will require the introduction of another chip. And the reason for this is something lacking in memory…. Read more »