6502 Build


This is it, a completed build... well hardware-wise. All I need now is to concentrate on the software side. It will be quite a challenge, as I haven't programmed in assembly for 30 years.

Comments

Post a Comment

Popular posts from this blog

To PLD or not to PLD

Image
When I start something interesting, I tend to overdo it. I originally contemplated using standard gates for my glue logic. But then chose to go the EEPLD (Electrically Erasable Programmable Logic Device) route. Wow, was I ambitious? Not only I was to build the 6502 single-board computer from the ground up, but I had to also get to know PLDs up close and personal at the same time. Well, it turns out it's not all that hard, if you find the right tutorials on the web, and if you have a precise memory map defined. I had this really particular memory map planned. But for my second iteration of the SBC, I opted to go simply and work my way up.  The map, for now, is 32K ROM, 16K IO space, and 16K RAM. This will change in the future. And this is the beauty of PLDs, there is no need to rewire anything. It's just the software that needs changing. I chose the ATF22V10C, a G22V10 equivalent, because of it's many input and output options: 12 dedicated inputs, and 10 configurable input/o...
Read more

Second iteration with "Hello World" working.

Image
It turns out I had an issue with my wiring AND the breadboard power supply could not provide enough power. So I scrapped all my wiring, not trusting it, and plugged in my bench power supply as a stable source. It took all day to rewire the board with the VIA and LCD, but it was worth it... or was it. Well, it turns out I had another mystery bug. And that one was very sneaky. It took me a while to catch on, but it turns out my EEPROM chip was defective. Darn! I only have one more in stock. I need to buy a few spares, just in case. But in the end, I got my "Hello World" to print on the LCD. That was quite satisfying! PS: Before you comment on my wiring, yes, I know, it's not as neat. But I didn't want to spend too much time on it. I need to know it works, and get to the next step, the ACIA and RTC. Because as soon as I know this works, I'll either etch my own board, or go the PCBWay!
Read more

First things first

Image
Before starting my adventure, I needed to do 2 things. Reorganize my lab space, and buy the necessary components. I wasn't quite ready to start my project, space-wise, as my office/lab was a mess and all my existing components were all thrown in various bins haphazardly.  Step one , reorder the furniture and optimize my desk space. Easier said than done, but I managed to do it in less than a day. Keep in mind that my "office" was also a dumping ground for everything else in the apartment. So I made some hard choices on what had to go and what stayed,  Mari Kondo style. It's not perfect, but it's a start. The following day, I sorted all my components, mostly because I was curious to find out what I had. And hold and behold, I had many unnecessary duplicates. That's what happens when you let me loose in my local electronics store without a shopping list or a plan. Step two , order the components needed. I chose Mouser because they carried the WD65C02 microproc...
Read more