Grant Searle's 6 Chip 68B09 SBC

I'm spending some vacation time I've earned building some of the SBCs I have collected over the years. I'm having a bit of difficulty find some tools, then a burnt out oscilloscope, and some trouble with burning my flash PROMs. I figured out the asm/convert/burn process so now burning the PROM isn't an issue anymore. I have a 63C09 CPU that doesn't work. I need to check the other 9 and see if any work. The 68B09 works fine. So far I have completed a lot of soldering, some programming in assembly language & BASIC and some debugging. I found Jeff Tranter's 6809 SBC code and forked it. I'll be updating my SBC github repos with the updated code. Seems the code contains assembly code outside the ROM address range. The ROM code copies the code down into the RAM so I don't know why there are op-codes in the RAM area of the source asm file. It's been there since Grant modified the CoCo Extended BASIC code. I'm currently using Jeff's combined code (BASIC, Trace, Disassembler and Assist09). I may have a problem with home made pull up resistor pack (fixed). It doesn't always start up except when I touch the home made resistor pack (now it works every time).

I haven't yet figured out how to get ef09 (eForth) in ROM yet but I did get it to work with SBC09 - the 6809 emulator. I'll post my modified SBC09 code up to my github account later. I also found an article on how to single step a 6809. Pretty neat but not sure what good it in in the current state. Might be useful with some more electronics and some LEDs on the address lines. I'll need to spend some time putting all the information and my notes into a web page.

And for those that wonder why? Well it's fun! I get to use everything I learned in school (EET & CS degrees), build something and bring back memories of when I first got into this line of work. What a long strange trip it's been!