DigicoolThings Forum

Having finally assembled an initial 6809 based MECB system, following the completion of my recent Motorola I/O + Sound Card, we should now give the system a bit more thorough testing.

Join me, as I first test the system running at twice speed, and then walk-through several test programs to verify everything, including Interrupts and Sound, are all working, and at the faster system speed, here:
Minimalist Europe Card Bus (MECB) – 6809 Testing, Coding, Sound!

This is really great and I'm getting really close (and excited) to completing the full set of MECB cards (bus, 6809, I/O, and graphics) - I'm just waiting for some final components to be shipped across (the reset circuit for the 6809 card and the memory chips for the graphics card). I'd be interested in replicating some of your tests on the completed system. Getting ASSIST09 running will be the obvious first confirmation of much of the system operating but I was wondering if you happen to have any of your basic graphics test code and Christmas-demo test code available somewhere for download? It would save me a lot of effort in trying to replicate it and would be useful to test the sound/graphics.

epaell wrote: ↑Sun Mar 10, 2024 12:34 am This is really great and I'm getting really close (and excited) to completing the full set of MECB cards (bus, 6809, I/O, and graphics) - I'm just waiting for some final components to be shipped across (the reset circuit for the 6809 card and the memory chips for the graphics card).

Thanks. This is awesome to hear. I look forward to hearing more about your MECB journey.

epaell wrote: ↑Sun Mar 10, 2024 12:34 am I'd be interested in replicating some of your tests on the completed system. Getting ASSIST09 running will be the obvious first confirmation of much of the system operating but I was wondering if you happen to have any of your basic graphics test code and Christmas-demo test code available somewhere for download? It would save me a lot of effort in trying to replicate it and would be useful to test the sound/graphics.

You can find all the code on the MECB Github repository (including Initial test and the Christmas demo). It's linked from the MECB homepage.

Here's the direct Github link: https://github.com/DigicoolThings/MECB

I plan to add more to the Github repository, as the project evolves further.

Hope this helps. Have fun!

Brilliant - thanks you so much for that - I'm clearly going blind as I totally missed the GitHub link previously.

I've cloned the repository and managed to compile them (after a bit of effort to get asm6809 installed on a Mac) - so I'm ready to go as soon as the TC4422 chip arrives (which is all I need to start testing the 6809 board and I/O board. I've also got a 63C09P[sic] - I'm so glad I saw your video on the chip relabelling - otherwise I probably would've tried it, found it not to work, and just assumed that I got sent a fake. I'm still not sure if this device will indeed work but once I've tested it with a working 6809P I'll add the "E" circuitry and see if I can get the 3 MHz processor working.

epaell wrote: ↑Sun Mar 10, 2024 2:25 am ... so I'm ready to go as soon as the TC4422 chip arrives (which is all I need to start testing the 6809 board and I/O board.

I'm assuming you meant TC1232CPA ? (for the reset circuit)

epaell wrote: ↑Sun Mar 10, 2024 2:25 am I've also got a 63C09P[sic] - I'm so glad I saw your video on the chip relabelling - otherwise I probably would've tried it, found it not to work, and just assumed that I got sent a fake. I'm still not sure if this device will indeed work but once I've tested it with a working 6809P I'll add the "E" circuitry and see if I can get the 3 MHz processor working.

Yes, it seems to be pot-luck what you actually end up with, from the usual sources of these retro chips. Hence, having a CPU Card that can be configured either-way seemed like the obvious solution. Therefore, whatever working '09 CPU chip you end up with is usuable on the card.

Oh no, I ordered the wrong device - how the heck did I get that wrong?!?! Oh well, new order just submitted now (at least this one has a shorter delivery time ).

epaell wrote: ↑Sun Mar 10, 2024 5:09 am Oh no, I ordered the wrong device - how the heck did I get that wrong?!?! Oh well, new order just submitted now (at least this one has a shorter delivery time ).

Whoops! Well, I'm glad I asked. Hopefully that was of some help (albiet frustrating).

Indeed, lucky I actually wrote the device number AND that you noticed it otherwise once it arrived I probably would've plugged it straight in and would have no idea why the board wasn't working (well, not without a great deal more debugging). It's still frustrating that it'll be a few more weeks before I can test this though. Thanks for pointing it out though!

Good news, finally received my reset circuit (the right one this time). I just tried the 6809 board with the I/O board and I get the ASSIST09 prompt and serial seems to work at 38400 baud - woohoo! I also removed my Motorola 6809 and inserted the Hitachi 63C09 that I ordered (with the 74HCT73 clock circuitry added, jumper removed, and 12 MHz crystal module instead of the 4 MHz one) and that too seems to work! This is now, by far, the fastest 6809 I have ever had!

I was hoping to test the sound and graphics card but ran into a problem where I couldn't load the S19-format data. ASSIST09 appears to start reading but then decides it doesn't like it. I seem to recall reading on Jeff Tranter's Blog that he ran into a checksum issue when working with asm6809 (he mentions that he fixed the code but not how). I'm curious - did you happen to run into this issue as well? I must admit that I'm using a Mac (via minicom) to do this so it is possible that there is something else going on. I just thought I'd check whether you had to do anything special or whether it just worked out of the box (as I probably won't have time to do more debugging until the weekend ).

Also confirmed that I can step up the crystal module on the I/O board to allow it to work at 115,200 baud!