My MECB cards

[lenzjo]

I had a git frenzy this morning I have uploaded most of the cards I've completed so far. These comprise of:

1> TMS9118 based VDP card. This also has a YM2413 sound chip on it. Though I'm still not happy the picture quality.

2> The 6502 CPU card - still in testing.

3> The extended back plane.

4> My first template card. This has dual power rails on each side and one down the middle. The remainder of the holes are in rows of 5 groups of three so that you can use either .3 or .6 wide chips and still have holes eaither side of them.

5> And lastly, my second template card, this time with space for a 16v8. After soldering all the bits to it I thought why not add some bread boards? so here's the result:

This time I used female headers, so I can poke wires into them, there's also a three pin socket that connects to the 3 cs outputs for easy access.

I haven't uploaded the I/o card yet as it is still in "what should it have" territory.

All the repositories have an image of the card (3d render) and the schematic is in pdf format so you don't have to fire up Kicad to see what's going on.

[Editor]

I had a git frenzy this morning I have uploaded most of the cards I've completed so far. These comprise of...

Awesome work!

Funnily enough, I'm about 75% through filming my MECB 6502 CPU Card YouTube video. I've actually had my prototype PCB's since December last year (v1.0 schematic done in November), so I'm really embarrised that life put these on the shelf for the last 6 months (Flood recovery projects and all).

But, this video should be my next one out. Phew.

... And lastly, my second template card, this time with space for a 16v8. After soldering all the bits to it I thought why not add some bread boards? so here's the result:

I really like what you've done with the prototype Card in your Template-2.

I always intended on making a second Prototype card with the 16V8 in place, to speed-up peripheral card prototyping. But, I've survived with just the header pin Bus access on my existing v1 Prototype card, and in many cases these days I'm just bypassing the breadboard / rats-nest process, given how cheap and easy it is to just jump-ahead to design a "prototype" PCB these days.

But I might look at getting me some of your Template-2 cards to play with.

[lenzjo]

Funnily enough, I'm about 75% through filming my MECB 6502 CPU Card YouTube video. I've actually had my prototype PCB's since December last year (v1.0 schematic done in November), so I'm really embarrised that life put these on the shelf for the last 6 months (Flood recovery projects and all).

But, this video should be my next one out. Phew.

Mine is STILL in the testing stage. I have MOS, Synertek and Rockwell 6502's along with the WDC one. The Synertek one will not play ball on my card. The others are okay. It's not faulty as I've had it on a breadboard and done the NOP dance with it. I also built up a Ben Eater style setup on breadboard but it doesn't work there and the others do with minor changes to some pin connections. It's starting to look as if it hasn't got the drive power and needs buffering. I'm beginning to think why bother? I will not be using any of the old 6502's on the card. And how many others would? Maybe I should just cut my loses and make the card WDC only.

[lenzjo]

I really like what you've done with the prototype Card in your Template-2.

I always intended on making a second Prototype card with the 16V8 in place, to speed-up peripheral card prototyping. But, I've survived with just the header pin Bus access on my existing v1 Prototype card, and in many cases these days I'm just bypassing the breadboard / rats-nest process, given how cheap and easy it is to just jump-ahead to design a "prototype" PCB these days.

But I might look at getting me some of your Template-2 cards to play with.

I'm a bit more cautious, I like to know that somethings got a fair chance of working and that I can program it. For example, I have A Xilinx 6572 CPLD from Daryl that's programmed as an SPI master. I want to read/write SD cards with it, so I am working out how to do it on a template-2 card. Not only that but the cards I want to make are multi-function, template-2 allows me to work on each part without distraction.

[Editor]

Mine is STILL in the testing stage. I have MOS, Synertek and Rockwell 6502's along with the WDC one. The Synertek one will not play ball on my card. The others are okay. It's not faulty as I've had it on a breadboard and done the NOP dance with it. I also built up a Ben Eater style setup on breadboard but it doesn't work there and the others do with minor changes to some pin connections. It's starting to look as if it hasn't got the drive power and needs buffering. I'm beginning to think why bother? I will not be using any of the old 6502's on the card. And how many others would? Maybe I should just cut my loses and make the card WDC only.

Interesting. I'm currently just building my first prototype Card, so we'll see how that goes (see my seperate note on my current CPU Card prototyping method).

I'm only targeting the original MOS 6502 and the currently in production WDC processors. I figured that most people would probably prefer a modern / new WDC W65C02S chip for it's reliability and speed potential. But, I just added original MOS 6502 support to allow some nostalgic retro chip support.

[Editor]

I'm a bit more cautious, I like to know that somethings got a fair chance of working and that I can program it. For example, I have A Xilinx 6572 CPLD from Daryl that's programmed as an SPI master. I want to read/write SD cards with it, so I am working out how to do it on a template-2 card. Not only that but the cards I want to make are multi-function, template-2 allows me to work on each part without distraction.

Don't get me wrong. I probably shouldn't have used the word "bypassing"! The prototyping stage is actually the most enjoyable part of the whole process, when you get to take your theoretical initial design notes and datasheet study, into a practical and observable test!

To explain what I meant more clearly: In the same way that I've modernised my old Wire-wrap microprocessor system design process, to a modern PCB process, I've done similar to my prototyping process.

Where I would previously wire-up a microprocessor circuit on breadboards for testing, I now find it an improved modern process to just preemptively route a PCB in KiCAD and order a prototype PCB, than it is to connect up a microprocessor circuit via a breadboard (together with all the issues of breadboard capacitance & inductance).

Sure, I might go through one or two PCB iterations, as I optimise the circuit, and I might end up cutting some PCB traces and wiring in some jumpers. But, I've found this a quicker and more enjoyable prototyping process, than playing with an excessive number of data & address bus jumper leads, often across multiple breadboards. It also fast-tracks towards the final PCB routing design.

Now, I do also qualify this by saying: This does pretty much only apply to microprocessor circuits, due to the number of Bus connections etc. I certainly still have many breadboards lying around with smaller (and partial) circuits, that I have enjoyed testing and optimising, via breadboard.

[bugeyedcreepy]

I had a git frenzy this morning I have uploaded most of the cards I've completed so far. These comprise of:

1> TMS9118 based VDP card. This also has a YM2413 sound chip on it. Though I'm still not happy the picture quality.

2> The 6502 CPU card - still in testing.

3> The extended back plane.

4> My first template card. This has dual power rails on each side and one down the middle. The remainder of the holes are in rows of 5 groups of three so that you can use either .3 or .6 wide chips and still have holes eaither side of them.

5> And lastly, my second template card, this time with space for a 16v8. After soldering all the bits to it I thought why not add some bread boards? so here's the result:

Template-2.jpg

This time I used female headers, so I can poke wires into them, there's also a three pin socket that connects to the 3 cs outputs for easy access.

I haven't uploaded the I/o card yet as it is still in "what should it have" territory.

All the repositories have an image of the card (3d render) and the schematic is in pdf format so you don't have to fire up Kicad to see what's going on.

Omg, Awesome!! Dang I wish I weren't in the middle of prepping a house sale and moving...!!