[v1.2] MECB Motorola I/O + Sound Card

[Editor]

i tryed some changes on my cpu board, the processor is an EF68B09EP, so no oscillator on he chip
i removed the JP2, just connected on 1 side.

Good. Assuming also, that the CPU chip is correctly marked.
I did have some issues with falsely re-marked 6809 chips. i.e. 6809P that were really 6809EP, and 6809EP that were really 6809P (although this is rarer as the 6809EP are more common).

the JP1 is just connected to 1 pin

JP1 Jumper should be on! It is the ROM Write Enable, which (by default), you want the jumper on 'RO' (Read Only), which pulls-up the Write / Program pin.

sw2 is A15 and A14 is off-------- A13,1A12,A11,A10,A9,A8 is ON

This switch setting is correct for $C0xx IORQ bank. Which matches well with the 48K + 16K Memory Map (indicated on you PLD label).

However, you still have the issue of possibly using an ASSIST09 ROM assembled for the 56K + 8K Memory Map, also expecting the IORQ Bank to be at $E0xx.

The original ASSIST09 (with this 56K/8K configuration), expects RAM to extend to $DFFF (where the Stack and Workspace is located).

To resolve this you will either need to re-program the ROM with a 48K/16K/C0 varient of ASSIST09 (.bin image available from MECB Github),
OR, re-program the PLD chip for the 56K/8K Memory map (.jed file also available from MECB Github).

To program either the ROM or the PLD will require a EPROM Programmer like the TL866 series (which hopefully you have handy?).

[tarix76]

I'm having trouble finding the BOM for this. The other boards have pdfs on GitHub but I'm failing to find one for the I/O board.

[Editor]

I'm having trouble finding the BOM for this. The other boards have pdfs on GitHub but I'm failing to find one for the I/O board.

Apologies for this oversight.

There is the full BOM in the Tindie Store listing description, and it also appears as a product image (.png) on the Tindie Store listing.

As you've pointed out it was missing on Github, I've now just added the lastest version of the BOM (as both .pdf and .png), to the Github folder.

Hopefully this helps also.

You'll probably also note from the latest BOM (now on Github), that I'm just in the process of updating the Tindie Store Motorola I/O Card listing to now include all the optional Packs required to make up a full Kitset (including pre-tested 'B' 2Mhz Motorola parts). I'm probably just a few days away from getting this completed (now that I have all parts in sufficient stock).

Upgrading older Tindie Store listings to provide full Kitsets was something I mentioned in my recent "future plans" video, as I've had a couple of people mention this would be helpful.

[tarix76]

There is the full BOM in the Tindie Store listing description, and it also appears as a product image (.png) on the Tindie Store listing.

I knew there was somewhere I forgot to look! I even asked Gemini before I posted and it wrote this ...

Visit the Tindie listing linked above — it includes the BOM in the description (with a photo/outline of components) and notes that the base purchase is often the PCB only, then you add optional packs, and source remaining parts from the BOM.

That will teach me to try and search for things on my phone while I'm distracted.

I'm going to go sit in time-out and study these parts lists.

[Editor]

I'm going to go sit in time-out and study these parts lists.

I trust you are progressing well with your parts lists.

It's pretty much taken me the whole day, but I've now finally fully refreshed the Tindie Store listing (and Github), for the MECB Motorola I/O + Sound Card.

I now finally offer a full kitset of all the parts needed for assembly. These are split into selectable "Packs", so people can choose only what they need (if they already have some parts in their stock).

In doing this, I also sourced (over the last month or so), the various Motorola recovered retro parts (all 2MHz "B" speed rated), and sound chips, from several different sources, and then pre-tested each in-circuit. Interestingly, about a 10% failure rate (the failed chips were then binned).

Hopefully this exercise will make it easier (going forward), for enthusiasts wanting to build their Motorola I/O Card.

Minimalist ECB (MECB) - Motorola I/O Card (on Tindie)

[tarix76]

I trust you are progressing well with your parts lists.

Everything should be on it's way to me now. I think I ended up buying enough CPU components for 10 boards or so. I'm guessing over the next few years I'll have built every 6809 kit there is.

It's pretty much taken me the whole day, but I've now finally fully refreshed the Tindie Store listing (and Github), for the MECB Motorola I/O + Sound Card.

I'm not sure how much you want to dumb things down but the IDC Headers gave me a little trouble. I would have loved to have an example part number for these. Here's what I bought:

https://www.digikey.com/en/products/det ... 21/4846930
https://www.digikey.com/en/products/det ... A/10414809

I now finally offer a full kitset of all the parts needed for assembly.

In the end I had fun figuring out how to order everything, in fact I specifically did not order the pre-programmed PLDs option because I want to know how to program them, but there is definitely a ton of value in having a full kit. This is especially important for chips like the V9958 where there is a lot of incentive to sell counterfeit or bad chips.

[Editor]

Everything should be on it's way to me now. I think I ended up buying enough CPU components for 10 boards or so. I'm guessing over the next few years I'll have built every 6809 kit there is.

That's probably wise (over ordering), especially with the recovered "out of production" retro parts.

In my experience I average about 10% failure rate on the parts (some orders are much worse). So, it's always advisable to order any of these parts in multiples (once you know you have a good supplier - see below).

I'm not sure how much you want to dumb things down but the IDC Headers gave me a little trouble. I would have loved to have an example part number for these. Here's what I bought...

You should be fine. I buy from mutliple sources, and different manufacturers. For the IDC boxed headers, most brands seem to be very similar dimensions. I think with the PCB layout I also just used a generic footprint, so the only difference you might experience is perhaps the right-angle header not lining up perfectly with the PCB edge (which would not actually be an issue).

In the end I had fun figuring out how to order everything, in fact I specifically did not order the pre-programmed PLDs option because I want to know how to program them, but there is definitely a ton of value in having a full kit. This is especially important for chips like the V9958 where there is a lot of incentive to sell counterfeit or bad chips.

Do you have a programmer like the TL866 family? If so, actual programming of the ATF16V8 or ATF22V10 PLDs is very straight-forward.
I even include the .jed files on the Github, so you can just directly program the .jed images.

However, I do highly recommend installing the new WinCUPL II (from Microchip), and getting familiar with editing the .pld source files and generating your own .jed files for programming.

p.s. You make a good observation about the V9958. As mentioned in one of my videos, I actually wasted several hundred US$ buying fake V9958 from different sources. Several 100% failure rate orders (and no refunds were given!).
I'm now very careful ordering these, usually with a single sample first, and if it tests okay, I'll folllow-up with ordering a few more.
But the challenge is that these are getting rare, and sometimes I've received a good sample order, only to find that the remaining stock has then sold out.

[tarix76]

Do you have a programmer like the TL866 family? If so, actual programming of the ATF16V8 or ATF22V10 PLDs is very straight-forward.
I even include the .jed files on the Github, so you can just directly program the .jed images.

Yes, I bought the T48 from AliExpress, which it seems like is the hobbiest favorite, so I think I'm all sorted

However, I do highly recommend installing the new WinCUPL II (from Microchip), and getting familiar with editing the .pld source files and generating your own .jed files for programming.

Thanks, I'll check that out. My strategy lately has been to search for everything on YouTube before I do anything because someone out there has made a video about it.