DigicoolThings Forum

hello sir
can you look once on that board.
the processor is an HD63C09EC, so normaly no oscillator build in
is SW3 correct, on "C"

Greetings cream51,
The jumpers look correct but the dip and rotary switches are not right.
The dip settings are the inverse of what they should be. switch 7 & 8 should be off (1) 1 to 6 should be on (0) to set the I/o address to 0xC000
The rotary switch should be set to 0 for Assist09 or 1 for Basic09.
Do you have any tools to help diagnose your problems? I find a logic probe indispensable for initial testing.
htht, Best regards, David.
Edit, this is my second attempt to reply. The first one never made it to the forum for some reason when I posted it.

cream51 wrote: Wed Dec 24, 2025 10:04 am can you look once on that board.
the processor is an HD63C09EC, so normaly no oscillator build in
is SW3 correct, on "C"

Sorry, I somehow missed this message.

But, it looks like David has you covered. Thanks David!

I'll just add one more thing: The 'ROM WE' header should have a jumper. Normally you would have this in the 'RO' (Read Only) position. This provides a pull-up on the ROM program /write pin.

hello sir
thanks for the help,,and you put me on the solving track.
now both 6809-6309 cards are working.

many thanks

cream51 wrote: Mon Jan 05, 2026 1:29 am thanks for the help,,and you put me on the solving track.
now both 6809-6309 cards are working.

So glad to hear you're now up and running.

Have fun!

hello sir,
i am interessed in the oled card, can that be programmed by my 6809 cards?
or do i need other cards as well
i mean, can you see on the oled screen ,the assist09 screen
many thanks

cream51 wrote: Sun Feb 22, 2026 11:13 pm i mean, can you see on the oled screen ,the assist09 screen

The OLED Card provides an 8-bit interfaced connection to the MECB bus (defaulting to IORQ 0x88-0x8F).

It works great with a 6809, but note that ASSIST09 is natively written for ACIA based serial I/O.

If you want to redirect character output to the OLED screen, you’d need to implement an ASSIST09 extension (e.g. to redefine the ‘OUTCH’ vector), for the ASSIST09 monitor, to provide the output drivers to send character output to the OLED, either, as well as, or, in place of, the serial output.

This isn’t something I’ve implemented (as yet), but it would be a logical first-step in making a fully stand-alone ASSIST09 based 6809 system.

Someone else may have already implemented this, or, it would certainly be a nice little project to code.