DigicoolThings Forum

Hi,

I'm Paul and I built my first microcomputer in my Dad's garage sometime around 1977 - as many did at the time.

I had just started an Electrical Engineering degree and we were going to be using 6800 microcomputers in second year. By salvaging some offcuts for a box, striping parts out of old radios and TVs for the power supply, and rewiring an old calculator for I/O, I was able to build a 6800 micro (with 6875 clock and 256 bytes of RAM). After months of tinkering I managed to get it to blink an LED - my parents were both very underwhelmed.

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I had big plans for this post degree (eg 6809, 68000), but life happened, I had a career in corporate software, and the world moved on.

Now that I have retired I have been enjoying watching people with their retro computers on YouTube - when I noticed people reviving retro projects with modern parts (which cost near to nothing compared to the equivalent in the 1980s) and decided to "rescue" my old projects from my mate's shed where they have been collecting dust for the past forty years.

Which is when I found this MECB project, that is what I always imagined how my projects would have looked - if the means were available back in 1977!

I’m planning on building a MECB 6809 project, then adding a 6502 board.

Looking forward to sharing and discussing our progress.

Thanks.

Welcome Paul. It's great to see you here on the forum. I look forward to hearing more about your retro rediscovery journey.

I think you'll find a group of fellow enthusiasts here, who all share similar stories of how they got started with microprocessors back in the day.

Your comment about MECB describes exactly what drove me to define it. Rediscovering my stored early projects, and taking the original process I'd used with wire-wrap and Eurocards (back in the early days), and modernising to take advantage of today's PCB design tools and ease of PCB manufacturing! Also, knowing that the chips of the 8-bit era, that took weeks of teenage pay-packets to save-up for back then, are now available to us cheaply.
Overall, capability that would have seemed like a science fiction dream come true, back then.

Have fun, and enjoy your re-discovery journey!

Greetings Paul,
6809, 6502, what more could you want. I'm finding the MECB much more satisfying that the other Z80 based retro system I also have. But I'm about to make a bridging adaptor so I can use cards from it on the MECB.

I too started my MECB journey after trying to get my old homebrew system working again but got pleasantly sidetracked with the new system.
Best regards, David.

Thanks!

Having been out of electronics for about forty years I'm finding it a bit like being a time traveler. All the things that made sense in the 1980's have been turned on their heads. At uni there was a 'Logic Analyser', only the Senior Lecturer was allowed anywhere near it as it was rumoured to cost as much as a new car - I just bought the modern equivalent for $10. Back then a microprocessor was an exotic and rare thing that was reserved for only the most important and critical tasks - now new designs are regularly using microcontrollers (with more power than we could have imaged) to blink an LED since microcontrollers can cost as little as 20 cents in bulk. Making a PCB was the last step in a long process of testing your design - now you just send your prototype design off to be made, and if it doesn't work or you think of something better, you just send a revised version off.

It's a lot to get my head around - but it's going to be fun learning.

PaulShipley wrote: ↑Wed Nov 13, 2024 9:09 am At uni there was a 'Logic Analyser', only the Senior Lecturer was allowed anywhere near it as it was rumoured to cost as much as a new car - I just bought the modern equivalent for $10.

Indeed! I originally used a simple home-made logic probe as my only digital test instrument (aside from my analog multimeter), to debug all of my digital projects.
It was tough going, with many faults having to be resolved with mental logic and processes of elimination!
Nowadays, my relatively cheap modern logic analyser still blows my mind, in comparison.

PaulShipley wrote: ↑Wed Nov 13, 2024 9:09 am Making a PCB was the last step in a long process of testing your design - now you just send your prototype design off to be made, and if it doesn't work or you think of something better, you just send a revised version off.

It's an exciting re-discovery, and re-thinking of what we did back in the day! And refining old procedures. e.g. Where I used to fully prototype a new design on breadboards (or point-to-point veroboard), back in the day, I've now changed to only breadboard prototyping key circuit elements, and instead going straight to PCB design for prototyping.
It's easy and relatively cheap, even if you go through 3 PCB iterations as you finalise your design.

This updated approach also fast-tracks your projects, as you are able to get a head-start on the PCB design stage.

PaulShipley wrote: ↑Wed Nov 13, 2024 9:09 am It's a lot to get my head around - but it's going to be fun learning.

I know exactly what you are saying. When I left my career and had time once again to re-discover my electronics hobby (after so many years too busy with work), the first couple of years was an exciting journey of coming up to speed with the latest methodology and upgrading to the latest tools.

I also really enjoyed getting into SMD. My first new electronics design project was an analog design, and I iterated through several PCB versions as I learned the modern PCB design & manufacture process, and also went from my traditional TH components to making the transition to SMD, then firstly hot-air guns, and then stencils and a home-made reflow oven.

More recently, I've also come back to TH with my MECB retro projects.

But one thing is definitely for sure... it's a lot of fun! I actually think it's possibly even more fun for those of us who remember the way it used to be, as opposed to the current generation who take for granted what's now possible.